MAX15005BAUE+ ,4.5V to 40V Input Automotive Flyback/Boost/SEPIC Power-Supply ControllersFeaturesThe MAX15004A/B/MAX15005A/B high-performance, ● Wide Supply Voltage Range Meets Automotive ..
MAX15006AASA+T ,40V, Ultra-Low Quiescent-Current Linear Regulators in 6-Pin TDFN/8-Pin SOElectrical Characteristics(V = 14V, I = 1mA, C = 0.1μF, C = 2.2μF, T = T = -40°C to +125°C, unless ..
MAX15006AATT+ ,40V, Ultra-Low Quiescent-Current Linear Regulators in 6-Pin TDFN/8-Pin SOFeatures● Wide Operating Input Voltage Range (4V to 40V)The MAX15006/MAX15007 ultra-low quiescent-c ..
MAX15006BASA+T ,40V, Ultra-Low Quiescent-Current Linear Regulators in 6-Pin TDFN/8-Pin SOApplicationsPART TEMP RANGEPACKAGE MARK● AutomotiveMAX15006AASA+ -40°C to +125°C 8 SO-EP* —● Tire-P ..
MAX15006BATT+ ,40V, Ultra-Low Quiescent-Current Linear Regulators in 6-Pin TDFN/8-Pin SOElectrical Characteristics(V = 14V, I = 1mA, C = 0.1μF, C = 2.2μF, T = T = -40°C to +125°C, unless ..
MAX15007AASA+ ,40V, Ultra-Low Quiescent-Current Linear Regulators in 6-Pin TDFN/8-Pin SOFeatures● Wide Operating Input Voltage Range (4V to 40V)The MAX15006/MAX15007 ultra-low quiescent-c ..
MAX4126 ,Single/Dual/Quad, Wide-Bandwidth, Low-Power, Single-Supply Rail-to-Rail I/O Op AmpsFeaturesThe MAX4122–MAX4129 family of operational amplifiers♦ 5-Pin SOT23 Package (MAX4122/4)combin ..
MAX4126ESA ,Dual, wide-bandwidth, low-power, single-supply Rail-to-Rail I/O op amp. BW 5MHz.Applications Pin Configurations appear at end of data sheet.__________Typical Operating CircuitSele ..
MAX4126ESA ,Dual, wide-bandwidth, low-power, single-supply Rail-to-Rail I/O op amp. BW 5MHz.FeaturesThe MAX4122–MAX4129 family of operational amplifiers' 5-Pin SOT23 Package (MAX4122/4)combin ..
MAX4126ESA ,Dual, wide-bandwidth, low-power, single-supply Rail-to-Rail I/O op amp. BW 5MHz.FeaturesThe MAX4122–MAX4129 family of operational amplifiers' 5-Pin SOT23 Package (MAX4122/4)combin ..
MAX4126ESA ,Dual, wide-bandwidth, low-power, single-supply Rail-to-Rail I/O op amp. BW 5MHz.ELECTRICAL CHARACTERISTICS (continued)(V = +2.7V to +6.5V, V = 0V, V = 0V, V = V /2, R tied to V /2 ..
MAX4126ESA+ ,Single/Dual/Quad, Wide-Bandwidth, Low-Power, Single-Supply Rail-to-Rail I/O Op AmpsELECTRICAL CHARACTERISTICS (V = +2.7V to +6.5V, V = 0V, V = 0V, V = V /2, R tied to V /2, SHDN ‡ 2V ..
MAX15005BAUE+
4.5V to 40V Input Automotive Flyback/Boost/SEPIC Power-Supply Controllers
General DescriptionThe MAX15004A/B/MAX15005A/B high-performance,
current-mode PWM controllers operate at an automotive
input voltage range from 4.5V to 40V (load dump). The
input voltage can go lower than 4.5V after startup if IN is
bootstrapped to a boosted output voltage. The controllers
integrate all the building blocks necessary for implementing
fixed-frequency isolated/nonisolated power supplies. The
general-purpose boost, flyback, forward, and SEPIC con-
verters can be designed with ease around the MAX15004/
MAX15005.
The current-mode control architecture offers excellent line-
transient response and cycle-by-cycle current limit while
simplifying the frequency compensation. Programmable
slope compensation simplifies the design further. A fast
60ns current-limit response time, low 300mV current-limit
threshold makes the controllers suitable for high-efficiency,
high-frequency DC-DC converters. The devices include
an internal error amplifier and 1% accurate reference to
facilitate the primary-side regulated, single-ended flyback
converter or nonisolated converters.
An external resistor and capacitor network programs the
switching frequency from 15kHz to 500kHz (1MHz for
the MAX15005A/B). The MAX15004A/B/MAX15005A/B
provide a SYNC input for synchronization to an
external clock. The maximum FET-driver duty cycle for the
MAX15004A/B is 50%. The maximum duty cycle can be
set on the MAX15005A/B by selecting the right combina-
tion of RT and CT.
The input undervoltage lockout (ON/OFF) programs the
input-supply startup voltage and can be used to shutdown
the converter to reduce the total shutdown current down
to 10µA. Protection features include cycle-by-cycle and
hiccup current limit, output over-voltage protection, and
thermal shutdown.
The MAX15004A/B/MAX15005A/B are available in space-
saving 16-pin TSSOP and thermally enhanced 16-pin
TSSOP-EP packages. All devices operate over the -40°C
to +125°C automotive temperature range.
Applications●Automotive●Vacuum Fluorescent Display (VFD) Power Supply●Isolated Flyback, Forward, Nonisolated SEPIC, Boost
Converters
Beneits and Features●Wide Supply Voltage Range Meets Automotive
Power-Supply Operating Requirement Including
“Cold Crank” Conditions 4.5V to 40V Operating Input Voltage Range (Can Operate at Lower Voltage After Startup if Input is Bootstrapped to a Boosted Output)●Control Architecture Offers Excellent Performance
While Simplifying the Design Current-Mode Control 300mV, 5% Accurate Current-Limit Threshold
Voltage Programmable Slope Compensation 50% (MAX15004) or Adjustable (MAX15005) Maximum Duty Cycle●Accurate, Adjustable Switching Frequency and
Synchronization Avoids Interference with Sensitive
Radio Bands Switching Frequency Adjustable from 15kHz to 500kHz (1MHz for the MAX15005A/B) RC Programmable 4% Accurate Switching
Frequency External Frequency Synchronization●Built-In Protection Capability for Improved System
Reliability Cycle-by-Cycle and Hiccup Current-Limit
Protection Overvoltage and Thermal-Shutdown Protection -40°C to +125°C Automotive Temperature Range AEC-Q100 Qualified
Pin Configuration appears at end of data sheet.
Note: All devices are specified over the -40°C to +125°C temperature range.
+Denotes a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive qualified part.
*EP = Exposed pad.
PARTPIN-PACKAGEMAX DUTY CYCLE
MAX15004AAUE+16 TSSOP-EP*50%
MAX15004AAUE/V+16 TSSOP-EP*50%
MAX15004BAUE+16 TSSOP50%
MAX15004BAUE/V+16 TSSOP50%
MAX15005AAUE+16 TSSOP-EP*Programmable
MAX15005AAUE/V+16 TSSOP-EP*Programmable
MAX15005BAUE+16 TSSOPProgrammable
MAX15005BAUE/V+16 TSSOPProgrammable
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
Ordering Information
EVALUATION KIT AVAILABLE
IN to SGND ...........................................................-0.3V to +45V
IN to PGND ...........................................................-0.3V to +45V
ON/OFF to SGND ......................................-0.3V to (VIN + 0.3V)
OVI, SLOPE, RTCT, SYNC, SS, FB, COMP,
CS to SGND .....................................-0.3V to (VREG5 + 0.3V)
VCC to PGND ........................................................-0.3V to +12V
REG5 to SGND .......................................................-0.3V to +6V
OUT to PGND ..........................................-0.3V to (VCC + 0.3V)
SGND to PGND ....................................................-0.3V to +0.3V
VCC Sink Current (clamped mode) ....................................35mAOUT Current (< 10μs transient) .........................................±1.5A
Continuous Power Dissipation* (TA = +70°C)
16-Pin TSSOP-EP (derate 21.3mW/°C
above +70°C) ............................................................1702mW
16-Pin TSSOP (derate 9.4mW/°C above +70°C) ............754mW
Operating Junction Temperature Range ..........-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range ............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
(VIN = 14V, CIN = 0.1μF, CVCC = 0.1μF // 1μF, CREG5 = 1μF, VON/OFF = 5V, CSS = 0.01μF, CSLOPE = 100pF, RT = 13.7kΩ, CT = 560pF,
VSYNC = VOVI = VFB = VCS = 0V, COMP = unconnected, OUT = unconnected. TA = TJ = -40°C to +125°C, unless otherwise noted.
Typical values are at TA = +25°C. All voltages are referenced to PGND, unless otherwise noted.) (Note 1) (Figure 5)
*As per JEDEC51 Standard, Multilayer Board.
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
POWER SUPPLYInput Supply RangeVIN4.540.0V
Operating Supply CurrentIQVIN = 40V, fOSC = 150kHz23.1mA
ON/OFF CONTROLInput-Voltage ThresholdVONVON/OFF rising1.051.231.40V
Input-Voltage HysteresisVHYST-ON75mV
Input Bias CurrentIB-ON/OFFVON/OFF = 40V0.5µA
Shutdown CurrentISHDNVON/OFF = 0V1020µA
INTERNAL 7.4V LDO (VCC)Output (VCC) Voltage Set PointVVCCIVCC = 0 to 20mA (sourcing)7.157.47.60V
Line RegulationVIN = 8V to 40V1mV/V
UVLO Threshold VoltageV UVLO-VCCVCC rising3.153.53.75V
UVLO HysteresisVHYST-UVLO500mV
Dropout VoltageVIN = 4.5V, IVCC = 20mA (sourcing)0.250.5V
Output Current LimitIVCC-ILIMIVCC sourcing45mA
Internal Clamp VoltageVVCC-CLAMPIVCC = 30mA (sinking)10.010.410.8V
INTERNAL 5V LDO (REG5)Output (REG5) Voltage Set PointVREG5VCC = 7.5V, IREG5 = 0 to 15mA (sourcing)4.754.955.05V
Line RegulationVCC = 5.5V to 10V2mV/V
Dropout VoltageVCC = 4.5V, IREG5 = 15mA (sourcing)0.250.5V
Output Current LimitIREG5-ILIMIREG5 sourcing32mA
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
Absolute Maximum RatingsStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these
or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Electrical Characteristics
(VIN = 14V, CIN = 0.1μF, CVCC = 0.1μF // 1μF, CREG5 = 1μF, VON/OFF = 5V, CSS = 0.01μF, CSLOPE = 100pF, RT = 13.7kΩ, CT = 560pF,
VSYNC = VOVI = VFB = VCS = 0V, COMP = unconnected, OUT = unconnected. TA = TJ = -40°C to +125°C, unless otherwise noted.
Typical values are at TA = +25°C. All voltages are referenced to PGND, unless otherwise noted.) (Note 1) (Figure 5)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
OSCILLATOR (RTCT)Oscillator Frequency RangefOSCfOSC = 2 x fOUT for MAX15004A/B,
fOSC = fOUT for MAX15005A/B151000kHz
RTCT Peak Trip LevelVTH,RTCT0.55 x VREG5V
RTCT Valley Trip LevelVTL,RTCT0.1 x VREG5V
RTCT Discharge CurrentIDIS,RTCTVRTCT = 2V1.301.331.36mA
Oscillator Frequency Accuracy
(Note 2)
RT = 13.7kΩ, CT = 4.7nF,
fOSC (typ) = 18kHz-4+4
RT = 13.7kΩ, CT = 560pF,
fOSC (typ) = 150kHz-4+4
RT = 21kΩ, CT = 100pF,
fOSC (typ) = 500kHz-5+5
RT = 7kΩ, CT = 100pF,
fOSC (typ) = 1MHz-7+7
Maximum PWM Duty Cycle
(Note 3)DMAX
MAX15004A/B50MAX15005A/B,RT = 13.7kΩ, CT = 560pF,
fOSC (typ) = 150kHz
Minimum On-TimetON-MINVIN = 14V110170ns
SYNC Lock-In Frequency Range
(Note 4)RT = 13.7kΩ, CT = 560pF,
fOSC (typ) = 150kHz102200%fOSC
SYNC High-Level VoltageVIH-SYNC2V
SYNC Low-Level VoltageVIL-SYNC0.8V
SYNC Input CurrentISYNCVSYNC = 0 to 5V-0.5+0.5µA
SYNC Minimum Input Pulse Width50ns
ERROR AMPLIFIER/SOFT-STARTSoft-Start Charging CurrentISSVSS = 0V81521µA
SS Reference VoltageVSS1.2151.2281.240V
SS Threshold for HICCUP EnableVSS rising1.1V
FB Regulation VoltageVREF-FBCOMP = FB,
ICOMP = -500µA to +500µA1.2151.2281.240V
FB Input Offset VoltageVOS-FB
COMP = 0.25V to 4.5V,
ICOMP = -500µA to +500µA,
VSS = 0 to 1.5V+5mV
FB Input CurrentVFB = 0 to 1.5V-300+300nA
COMP Sink CurrentICOMP-SINKVFB = 1.5V, VCOMP = 0.25V35.5mA
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
Electrical Characteristics (continued)
(VIN = 14V, CIN = 0.1μF, CVCC = 0.1μF // 1μF, CREG5 = 1μF, VON/OFF = 5V, CSS = 0.01μF, CSLOPE = 100pF, RT = 13.7kΩ, CT = 560pF,
VSYNC = VOVI = VFB = VCS = 0V, COMP = unconnected, OUT = unconnected. TA = TJ = -40°C to +125°C, unless otherwise noted.
Typical values are at TA = +25°C. All voltages are referenced to PGND, unless otherwise noted.) (Note 1) (Figure 5)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSCOMP Source CurrentICOMP-
SOURCEVFB = 1V, VCOMP = 4.5V1.32.8mA
COMP High VoltageVOH-COMPVFB = 1V, ICOMP = 1mA (sourcing)VREG5
- 0.5
VREG5
- 0.2V
COMP Low VoltageVOL-COMPVFB = 1.5V, ICOMP = 1mA (sinking)0.10.25V
Open-Loop GainAEAMP100dB
Unity-Gain BandwidthUGFEAMP1.6MHz
Phase MarginPMEAMP75degrees
COMP Positive Slew RateSR+0.5V/µs
COMP Negative Slew RateSR--0.5V/µs
PWM COMPARATOR Current-Sense GainACS-PWMΔVCOMP/ΔVCS (Note 5)2.8533.15V/V
PWM Propagation Delay to OUTtPD-PWM
CS = 0.15V, from VCOMP falling edge:
3V to 0.5V to OUT falling (excluding
leading-edge blanking time)ns
PWM Comparator Current-Sense
Leading-Edge Blanking TimetCS-BLANK50ns
CURRENT-LIMIT COMPARATORCurrent-Limit Threshold VoltageVILIM290305317mV
Current-Limit Input Bias CurrentIB-CSOUT= high, 0 ≤ VCS ≤ 0.3V-2+2µA
ILIMIT Propagation Delay to OUTtPD-ILIM
From CS rising above VILIM (50mV
overdrive) to OUT falling (excluding
leading-edge blanking time)ns
ILIM Comparator Current-Sense
Leading-Edge Blanking TimetCS-BLANK50ns
Number of Consecutive ILIMIT
Events to HICCUP7
HICCUP Timeout512Clock
periods
SLOPE COMPENSATION (Note 6)Slope Capacitor Charging CurrentISLOPEVSLOPE = 100mV9.810.511.2µA
Slope CompensationCSLOPE = 100pF25mV/µs
Slope Compensation Tolerance
(Note 2)CSLOPE = 100pF-4+4%
Slope Compensation RangeCSLOPE = 22pF110mV/µsCSLOPE = 1000pF2.5
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
Electrical Characteristics (continued)
(VIN = 14V, CIN = 0.1μF, CVCC = 0.1μF // 1μF, CREG5 = 1μF, VON/OFF = 5V, CSS = 0.01μF, CSLOPE = 100pF, RT = 13.7kΩ, CT = 560pF,
VSYNC = VOVI = VFB = VCS = 0V, COMP = unconnected, OUT = unconnected. TA = TJ = -40°C to +125°C, unless otherwise noted.
Typical values are at TA = +25°C. All voltages are referenced to PGND, unless otherwise noted.) (Note 1) (Figure 5)
Note 1: 100% production tested at +125°C. Limits over the temperature range are guaranteed by design.
Note 2: Guaranteed by design; not production tested.
Note 3: For the MAX15005A/B, DMAX depends upon the value of RT. See Figure 3 and the Oscillator Frequency/External
Synchronization section.
Note 4: The external SYNC pulse triggers the discharge of the oscillator ramp. See Figure 2. During external SYNC, DMAX = 50%
for the MAX15004A/B; for the MAX15005A/B, there is a shift in DMAX with fSYNC/fOSC ratio (see the Oscillator Frequency/
External Synchronization section).
Note 5: The parameter is measured at the trip point of latch, with 0 ≤ VCS ≤ 0.3V, and FB = COMP.
Note 6: Slope compensation = (2.5 x 10-9)/CSLOPE mV/μs. See the Applications Information section.
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
OUTPUT DRIVERDriver Output Impedance
ROUT-NVCC = 8V (applied externally),
IOUT = 100mA (sinking)1.73.5
ROUT-PVCC = 8V (applied externally),
IOUT = 100mA (sourcing)35
Driver Peak Output CurrentIOUT-PEAKCOUT = 10nF, sinking1000mACOUT = 10nF, sourcing750
OVERVOLTAGE COMPARATOROvervoltage Comparator Input
ThresholdVOV-THVOVI rising1.201.2281.26V
Overvoltage Comparator
HysteresisVOV-HYST125mV
Overvoltage Comparator DelayTDOVIFrom OVI rising above 1.228V to OUT
falling, with 50mV overdrive1.6µs
OVI Input CurrentIOVIVOVI = 0 to 5V-0.5+0.5µA
THERMAL SHUTDOWNShutdown TemperatureTSHDNTemperature rising160°C
Thermal HysteresisTHYST15°C
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
Electrical Characteristics (continued)
VIN = 14V, CIN = 0.1μF, CVCC = 0.1μF // 1μF, CREG5 = 1μF, VON/OFF = 5V, CSS = 0.01μF, CSLOPE = 100pF, RT = 13.7kΩ,
CT = 560pF. TA = +25°C, unless otherwise noted.)
VIN SUPPLY CURRENT (ISUPPLY)
vs. OSCILLATOR FREQUENCY (fOSC)FREQUENCY (kHz)
SUPPLY CURRENT (mA)
MAX15004 toc0260110160210260310360410460510MAX15005
VIN = 14V
CT = 220pF
COUT = 10nF
COUT = 0nF
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGESUPPLY VOLTAGE (V)
SHUTDOWN SUPPLY CURRENT (µA)
MAX15004 toc031015202530354045
TA = +135°C
TA = -40°C
TA = +25°C
VCC OUTPUT VOLTAGE
vs. VIN SUPPLY VOLTAGEVIN SUPPLY VOLTAGE (V)
OUTPUT VOLTAGE (V)
MAX15004 toc041015202530354045
IVCC = 0mA
IVCC = 1mAIVCC = 20mA
REG5 OUTPUT VOLTAGE
vs. VCC VOLTAGEVCC VOLTAGE (V)
REG5 OUTPUT VOLTAGE (V)
MAX15004 toc06
IREG5 = 1mA (SOURCING)
IREG5 = 15mA (SOURCING)
REG5 DROPOUT VOLTAGE
vs. IREG5IREG5 (mA)
REG5 LDO DROPOUT VOLTAGE (V)
MAX15004 toc072468101214
TA = +135°C
TA = +25°C
TA = -40°C
TA = +125°CVCC = 4.5
VIN = VON/OFF
VIN UVLO HYSTERESIS
vs. TEMPERATURETEMPERATURE (°C)
UVLO HYSTERESIS (mV)
MAX15004 toc01
OSCILLATOR FREQUENCY (fOSC)
vs. VIN SUPPLY VOLTAGE
OSCILLATOR FREQUENCY (kHz)
MAX15004 toc08
TA = +125°C
TA = -40°CTA = +25°C
TA = +135°C
RT = 13.7kΩ
CT = 560pFMAX15005
OSCILLATOR FREQUENCY (fOSC)
vs. RT/CT OSCILLATOR FREQUENCY (kHz)
MAX15004 toc09101001000
CT = 220pF
CT = 1500pF
CT = 1000pF
CT = 560pF
CT = 2200pF
CT = 3300pF
CT = 100pF
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
Typical Operating Characteristics
VIN = 14V, CIN = 0.1μF, CVCC = 0.1μF // 1μF, CREG5 = 1μF, VON/OFF = 5V, CSS = 0.01μF, CSLOPE = 100pF, RT = 13.7kΩ,
CT = 560pF. TA = +25°C, unless otherwise noted.)
MAX15005 MAXIMUM DUTY CYCLE
vs. OUTPUT FREQUENCY (fOUT) OUTPUT FREQUENCY (kHz)
MAXIMUM DUTY CYCLE (%)
MAX15004 toc10
CT = 220pF
CT = 1500pF
CT = 1000pFCT = 560pF
CT = 2200pF
CT = 3300pF
CT = 100pF
MAX15004 MAXIMUM DUTY CYCLE
vs. TEMPERATURETEMPERATURE (°C)
MAXIMUM DUTY CYCLE (%)
MAX15004 toc1
fOUT = 75kHz
MAX15005 MAXIMUM DUTY CYCLE
vs. TEMPERATURETEMPERATURE (°C)
MAXIMUM DUTY CYCLE (%)
MAX15004 toc12
CT = 560pF
RT = 13.7kΩ
fOSC = fOUT = 150kHz
MAXIMUM DUTY CYCLE
vs. fSYNC/fOSC RATIOfSYNC/fOSC RATIO
MAXIMUM DUTY CYCLE (%)
MAX15004 toc13
CRTCT = 220pF
RRTCT = 10kΩ
fOSC = fOUT = 418kHz
CT = 560pF
RT = 10kΩ
fOSC = fOUT = 180kHz
MAX15005
ERROR AMPLIFIER OPEN-LOOP GAIN
AND PHASE vs. FREQUENCYFREQUENCY (Hz)
GAIN (dB)
MAX15004 toc14
PHASE (DEGREES)
0.11101001k10k100k1M10M
GAIN
PHASE
CS-TO-OUT DELAY vs. TEMPERATURETEMPERATURE (°C)
CS-TO-OUT DELAY (ns)
MAX15004 toc15
VCS OVERDRIVE = 190mV
VCS OVERDRIVE = 50mV
OVI TO OUT DELAY THROUGH
OVERVOLTAGE COMPARATORMAX15004 toc16
VOUT
2V/div
VOVI
500mV/div
VOUT
VOVI
DRIVER OUTPUT PEAK SOURCE
AND SINK CURRENTMAX15004 toc17
VOUT
5V/div
IOUT
1A/div
COUT = 10nF
POWER-UP SEQUENCE THROUGH VINMAX15004 toc18
VIN
10V/div
VCC
5V/div
REG5
5V/div
VOUT
5V/div
VON/OFF = 5V
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
Typical Operating Characteristics (continued)
VIN = 14V, CIN = 0.1μF, CVCC = 0.1μF // 1μF, CREG5 = 1μF, VON/OFF = 5V, CSS = 0.01μF, CSLOPE = 100pF, RT = 13.7kΩ,
CT = 560pF. TA = +25°C, unless otherwise noted.)
POWER-DOWN SEQUENCE THROUGH VINMAX15004 toc19
4ms/div
VIN
10V/div
VCC
5V/div
REG5
5V/div
VOUT
5V/div
VON/OFF = 5V
POWER-UP SEQUENCE
THROUGH ON/OFFMAX15004 toc20
1ms/div
ON/OFF
5V/div
VCC
5V/div
REG5
5V/div
VOUT
5V/div
POWER-DOWN SEQUENCE
THROUGH ON/OFFMAX15004 toc21
400ms/div
ON/OFF
5V/div
VCC
5V/div
REG5
5V/div
VOUT
5V/div
LINE TRANSIENT FOR VIN STEP
FROM 14V TO 5.5VMAX15004 toc22
100µs/div
VIN
10V/div
VCC
5V/div
REG5
5V/div
VOUT
5V/div
LINE TRANSIENT FOR VIN STEP
FROM 14V TO 40VMAX15004 toc23
100µs/div
VIN
20V/div
VCC
5V/div
REG5
5V/div
VOUT
5V/div
HICCUP MODE FOR FLYBACK CIRCUIT
(FIGURE 7)MAX15004 toc24
VCS
200mV/div
VANODE
1V/div
ISHORT
500mA/div
DRAIN WAVEFORM IN
FLYBACK CONVERTER (FIGURE 7)MAX15004 toc25
10V/div
ILOAD = 10mA
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
Typical Operating Characteristics (continued)
PINNAMEFUNCTIONINInput Power Supply. Bypass IN with a minimum 0.1µF ceramic capacitor to PGND.ON/OFF
ON/OFF Input. Connect ON/OFF to IN for always-on operation. To externally program the UVLO threshold of
the IN supply, connect a resistive divider between IN, ON/OFF, and SGND. Pull ON/OFF to SGND to disable the
controller.OVIOvervoltage Comparator Input. Connect a resistive divider between the output of the power supply, OVI, and
SGND to set the output overvoltage threshold.SLOPE
Programmable Slope Compensation Capacitor Input. Connect a capacitor (CSLOPE) to SGND to set the amount
of slope compensation.
Slope compensation = (2.5 x 10-9)/CSLOPE mV/µs with CSLOPE in farads.N.C.No Connection. Not internally connected.RTCTOscillator-Timing Network Input. Connect a resistor from RTCT to REG5 and a capacitor from RTCT to SGND to
set the oscillator frequency (see the Oscillator Frequency/External Synchronization section).SGNDSignal Ground. Connect SGND to SGND plane.SYNCExternal-Clock Synchronization Input. Connect SYNC to SGND when not using an external clock.SSSoft-Start Capacitor Input. Connect a capacitor from SS to SGND to set the soft-start time interval. FBInternal Error-Ampliier Inverting Input. The noninverting input is internally connected to SS.COMPError-Ampliier Output. Connect the frequency compensation network between FB and COMP.CSCurrent-Sense Input. The current-sense signal is compared to a signal proportional to the error-ampliier output
voltage.REG55V Low-Dropout Regulator Output. Bypass REG5 with a 1µF ceramic capacitor to SGND.PGNDPower Ground. Connect PGND to the power ground plane. OUTGate Driver Output. Connect OUT to the gate of the external n-channel MOSFET.VCC7.4V Low-Dropout Regulator Output—Driver Power Source. Bypass VCC with 0.1µF and 1µF or higher ceramic
capacitors to PGND. Do not connect external supply or bootstrap to VCC.EPExposed Pad (MAX15004A/MAX15005A only). Connect EP to the SGND plane to improve thermal performance.
Do not use the EP as an electrical connection.
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
Pin Description
MAX15004A/B
MAX15005A/BPREREGULATOR
REFERENCE
SLOPE
COMPENSATION
EAMP
REF-AMP
THERMAL
SHUTDOWN
OV-COMP
ON/OFF
COMP
OSCILLATOR
CONSECUTIVE
EVENTS
COUNTER
7.4V LDO
REG
5V LDO
REG
UVB
VCC
UVB3.5V
UVLO
50ns
LEAD
DELAY
DRIVER
0.3V
SS_OK
RESET
1.228V
1.228V
1.228VSYNC
SGND
RTCT
SLOPE
OVI
ON/OFF
VCC16
OUT15
PGND14
REG51312
COMP11109
OFF
OFF
SET
RESET
OVRLD
CLK
OVRLD
PWM-
COMP
ILIMIT
COMP
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
Functional Diagram
Detailed DescriptionThe MAX15004A/B/MAX15005A/B are high-performance,
current-mode PWM controllers for wide input-voltage
range isolated/nonisolated power supplies. These con-
trollers are for use as general-purpose boost, flyback,
and SEPIC controllers. The input voltage range of 4.5V
to 40V makes it ideal in automotive applications such as
vacuum fluorescent display (VFD) power supplies. The
internal low-dropout regulator (VCC regulator) enables the
MAX15004A/B/MAX15005A/B to operate directly from an
automotive battery input. The input voltage can go lower
than 4.5V after startup if IN is bootstrapped to a boosted
output voltage.
The undervoltage lockout (ON/OFF) allows the devices
to program the input-supply startup voltage and ensures
predictable operation during brownout conditions.
The devices contain two internal regulators, VCC and
REG5. The VCC regulator output voltage is set at 7.4V
and REG5 regulator output voltage at 5V ±2%. The input
undervoltage lockout (UVLO) circuit monitors the VCC
voltage and turns off the converter when the VCC voltage
drops below 3.5V (typ).
An external resistor and capacitor network programs
the switching frequency from 15kHz to 500kHz. The
MAX15004A/B/MAX15005A/B provide a SYNC input for
synchronization to an external clock. The OUT (FET-
driver output) duty cycle for the MAX15004A/B is 50%.
The maximum duty cycle can be set on MAX15005A/B by
selecting the right combination of RT and CT. The RTCT
discharge current is trimmed to 2%, allowing accurate
setting of the duty cycle for the MAX15005. An internal
slope-compensation circuit stabilizes the current loop
when operating at higher duty cycles and can be pro-
grammed externally.
The MAX15004/MAX15005 include an internal error
amplifier with 1% accurate reference to regulate the
output in nonisolated topologies using a resistive divider.
The internal reference connected to the noninverting input
of the error amplifier can be increased in a controlled
manner to obtain soft-start. A capacitor connected at SS
to ground programs soft-start to reduce inrush current and
prevent output overshoot.
The MAX15004/MAX15005 include protection features
like hiccup current limit, output overvoltage, and ther-
mal shutdown. The hiccup current-limit circuit reduces
the power delivered to the electronics powered by the
MAX15004/MAX15005 converter during severe fault con-
ditions. The overvoltage circuit senses the output using
the path different from the feedback path to provide
meaningful overvoltage protection. During continuous
high input operation, the power dissipation into the
MAX15004/MAX15005 could exceed its limit. Internal
thermal shutdown protection safely turns off the converter
when the junction heats up to 160°C.
Current-Mode Control LoopThe advantages of current-mode control overvoltage-
mode control are twofold. First, there is the feed-forward
characteristic brought on by the controller’s ability to adjust
for variations in the input voltage on a cycle-by-cycle
basis. Secondly, the stability requirements of the current-
mode controller are reduced to that of a single-pole
system unlike the double pole in voltage-mode control.
The MAX15004/MAX15005 offer peak current-mode
control operation to make the power supply easy to design
with. The inherent feed-forward characteristic is useful
especially in an automotive application where the input
voltage changes fast during cold-crank and load dump con-
ditions. While the current-mode architecture offers many
advantages, there are some shortcomings. For higher duty-
cycle and continuous conduction mode operation where
the transformer does not discharge during the off duty
cycle, subharmonic oscillations appear. The MAX15004/
MAX15005 offer programmable slope compensation using
a single capacitor. Another issue is noise due to turn-on
of the primary switch that may cause the premature end
of the on cycle. The current-limit and PWM comparator
inputs have leading-edge blanking. All the shortcomings of
the current-mode control are addressed in the MAX15004/
MAX15005, making it ideal to design for automotive power
conversion applications.
Internal Regulators VCC and REG5The internal LDO converts the automotive battery voltage
input to a 7.4V output voltage (VCC). The VCC output is
set at 7.4V and operates in a dropout mode at input volt-
ages below 7.5V. The internal LDO is capable of deliver-
ing 20mA current, enough to provide power to internal
control circuitry and the gate drive. The regulated VCC
keeps the driver output voltage well below the absolute
maximum gate voltage rating of the MOSFET especially
during the double battery and load dump conditions.
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
The second 5V LDO regulator from VCC to REG5 pro-
vides power to the internal control circuits. This LDO can
also be used to source 15mA of external load current.
Bypass VCC and REG5 with a parallel combination of
1µF and 0.1µF low-ESR ceramic capacitors. Additional
capacitors (up to 22µF) at VCC can be used although they
are not necessary for proper operation of the MAX15004/
MAX15005.
Startup Operation/UVLO/ON/OFFThe MAX15004A/B/MAX15005A/B feature two undervolt-
age lockouts (UVLO). The internal UVLO monitors the
VCC-regulator and turns on the converter once VCC rises
above 3.5V. The internal UVLO circuit has about 0.5V
hysteresis to avoid chattering during turn-on.
An external undervoltage lockout can be achieved by
controlling the voltage at the ON/OFF input. The ON/
OFF input threshold is set at 1.23V (rising) with 75mV
hysteresis.
Before any operation can commence, the ON/OFF volt-
age must exceed the 1.23V threshold.
Calculate R1 in Figure 1 by using the following formula:
UVLOR11R2V=−×
where VUVLO is the ON/OFF’s 1.23V rising threshold,
and VON is the desired input startup voltage. Choose an R2 value in the 100kΩ range. The UVLO circuits keep
the PWM comparator, ILIM comparator, oscillator, and
output driver shut down to reduce current consumption
(see the Functional Diagram). The ON/OFF input can be
used to disable the MAX15004/MAX15005 and reduce the standby current to less than 20μA.
Soft-StartThe MAX15004/MAX15005 are provided with an
externally adjustable soft-start function, saving a number
of external components. The SS is a 1.228V reference
bypass connection for the MAX15004A/B/MAX15005A/B
and also controls the soft-start period. At startup, after
VIN is applied and the UVLO thresholds are reached, the device enters soft-start. During soft-start, 15μA is sourced
into the capacitor (CSS) connected from SS to GND
causing the reference voltage to ramp up slowly. The
HICCUP mode of operation is disabled during soft-start.
When VSS reaches 1.228V, the output as well as the
HICCUP mode become fully active. Set the soft-start time
(tSS) using following equation:)SS6
1.23(V)Ct10A−×=×
where tSS is in seconds and CSS is in farads.
The soft-start programmability is important to control
the input inrush current issue and also to avoid the
MAX15004/MAX15005 power supply from going into the
unintentional hiccup during the startup. The required soft-
start time depends on the topology used, current-limit
setting, output capacitance, and the load condition.
Oscillator Frequency/External SynchronizationUse an external resistor and capacitor at RTCT to pro-
gram the MAX15004A/B/MAX15005A/B internal oscilla-
tor frequency from 15kHz to 1MHz. The MAX15004A/B
output switching frequency is one-half the programmed
oscillator frequency with a 50% maximum duty-cycle
limit. The MAX15005A/B output switching frequency is
the same as the oscillator frequency. The RC network
connected to RTCT controls both the oscillator frequen-
cy and the maximum duty cycle. The CT capacitor
charges and discharges from (0.1 x VREG5) to (0.55 x
VREG5). It charges through RT and discharges through an
internal trimmed controlled current sink. The maximum
duty cycle is inversely proportional to the discharge time
(tDISCHARGE). See Figures 3a and 3b for a coarse
selection of capacitor values for a given switching frequen-
cy and maximum duty cycle and then use the following
Figure 1. Setting the MAX15004A/B/MAX15005A/B
Undervoltage-Lockout Threshold
MAX15004A/B
MAX15005A/BON/OFF
1.23VR2
VIN
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
equations to calculate the resistor value to fine-tune the
switching frequency and verify the worst-case maximum
duty cycle.
MAXCHARGEOSC
CHARGE
DISCHARGE3
OSCCHARGEDISCHARGEOSC
CHARGEDISCHARGEtfRT0.7CT
2.25(V)RTCTt
(1.3310(A)RT)3.375(V)...................UseThisEquationIff500kHzttf1.......UseThisEquationtt160ns−×××=××≤+=++OSCIff500kHz>
where fOSC is the oscillator frequency, RT is a resistor
connected from RTCT to REG5, and CT is a capacitor
connected from RTCT to SGND. Verify that the oscilla-
tor frequency value meets the target. Above calculations
could be repeated to fine-tune the switching frequency.
The MAX15004A/B is a 50% maximum duty-cycle part,
while the MAX15005A/B is 100% maximum duty-cycle
part.
OUTOSCff2=
for the MAX15004A/B and
OUTOSCff=
for the MAX15005A/B.
The MAX15004A/B/MAX15005A/B can be synchronized
using an external clock at the SYNC input. For proper
frequency synchronization, SYNC’s input frequency must
be at least 102% of the programmed internal oscillator
frequency. Connect SYNC to SGND when not using an
external clock. A rising clock edge on SYNC is interpreted
as a synchronization input. If the SYNC signal is lost,
the internal oscillator takes control of the switching rate,
returning the switching frequency to that set by RC net-
work connected to RTCT. This maintains output regulation
even with intermittent SYNC signals.
n-Channel MOSFET DriverRTCT
CLKINT
SYNC
OUT
RTCT
CLKINT
SYNC
OUT
D = 50%D = 50%
D = 81.25%D = 80%
WITH SYNC
INPUT
MAX15004A/B (DMAX = 50%)
MAX15005A/B (DMAX = 81%)WITHOUT
SYNC INPUT
WITH SYNC
INPUT
WITHOUT
SYNC INPUT
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
OUT drives the gate of an external n-channel MOSFET.
The driver is powered by the internal regulator (VCC),
internally set to approximately 7.4V. The regulated VCC
voltage keeps the OUT voltage below the maximum gate
voltage rating of the external MOSFET. OUT can source
750mA and sink 1000mA peak current. The average
current sourced by OUT depends on the switching
frequency and total gate charge of the external MOSFET.
Error AmpliierThe MAX15004A/B/MAX15005A/B include an internal
error amplifier. The noninverting input of the error ampli-
fier is connected to the internal 1.228V reference and
feedback is provided at the inverting input. High 100dB
open-loop gain and 1.6MHz unity-gain bandwidth allow
good closed-loop bandwidth and transient response.
Moreover, the source and sink current capability of 2mA
provides fast error correction during the output load tran-
sient. For Figure 5, calculate the power-supply output
voltage using the following equation:OUTREFBV1VR=+
where VREF = 1.228V. The amplifier’s noninverting input
is internally connected to a soft-start circuit that gradu-
ally increases the reference voltage during startup. This
forces the output voltage to come up in an orderly and
well-defined manner under all load conditions.
Slope CompensationThe MAX15004A/B/MAX15005A/B use an internal ramp
generator for slope compensation. The internal ramp
signal resets at the beginning of each cycle and slews at
the rate programmed by the external capacitor connected
to SLOPE. The amount of slope compensation needed
depends on the downslope of the current waveform.
Adjust the MAX15004A/B/MAX15005A/B slew rate up to 110mV/μs using the following equation:
SLOPE
2.510(A)Slope compensation (mVµs)C×=
where CSLOPE is the external capacitor at SLOPE in
farads.
Current LimitThe current-sense resistor (RCS), connected between the
source of the MOSFET and ground, sets the current limit.
The CS input has a voltage trip level (VCS) of 305mV. The
current-sense threshold has 5% accuracy. Set the current-
limit threshold 20% higher than the peak switch current at
the rated output power and minimum input voltage. Use
the following equation to calculate the value of RS:()SCSPKRVI1.2=×
where IPRI is the peak current that flows through the
MOSFET at full load and minimum VIN.
Figure 3a. MAX15005 Maximum Duty Cycle vs. Output
Frequency.
Figure 3b. Oscillator Frequency vs. RT/CT
MAX15005 MAXIMUM DUTY CYCLE
vs. OUTPUT FREQUENCY (fOUT) OUTPUT FREQUENCY (kHz)
MAXIMUM DUTY CYCLE (%)
CT = 220pF
CT = 1500pF
CT = 1000pFCT = 560pF
CT = 2200pF
CT = 3300pF
CT = 100pF
OSCILLATOR FREQUENCY (fOSC)
vs. RT/CT RT (kΩ)
OSCILLATOR FREQUENCY (kHz)101001000
CT = 220pF
CT = 1500pF
CT = 1000pF
CT = 560pF
CT = 2200pF
CT = 3300pF
CT = 100pF
MAX15004A/B-MAX15005A/B4.5V to 40V Input Automotive
Flyback/Boost/SEPIC
Power-Supply Controllers
