MAX5033DUSA+T ,500mA, 76V, High-Efficiency, MAXPower Step-Down DC-DC ConverterApplicationsMAX5033BASA -40°C to +125°C 8 SO● Consumer ElectronicsMAX5033CUSA 0°C to +85°C 8 SO● In ..
MAX5033DUSA+T ,500mA, 76V, High-Efficiency, MAXPower Step-Down DC-DC ConverterElectrical Characteristics (MAX5033_U_ _) (continued)(V = +12V, V = +12V, I = 0, T = 0°C to +85°C, ..
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MAX5033AASA+-MAX5033AUSA+-MAX5033AUSA+T-MAX5033BASA+-MAX5033BASA+T-MAX5033BUSA+-MAX5033CUSA+-MAX5033DASA+-MAX5033DASA+T-MAX5033DUSA+-MAX5033DUSA+T
500mA, 76V, High-Efficiency, MAXPower Step-Down DC-DC Converter
General DescriptionThe MAX5033 easy-to-use, high-efficiency, high-voltage,
step-down DC-DC converter operates from an input volt-age up to 76V and consumes only 270μA quiescent cur-
rent at no load. This pulse-width modulated (PWM) con-verter operates at a fixed 125kHz switching frequency at
heavy loads, and automatically switches to pulseskipping mode to provide low quiescent current and high efficiency at light loads. The MAX5033 includes internal frequency
compensation simplifying circuit implementation. The
device uses an internal low-onresistance, high-voltage,
DMOS transistor to obtain high efficiency and reduce
overall system cost. This device includes undervoltage
lockout, cycle-by-cycle current limit, hiccup-mode output
short-circuit protection, and thermal shutdown.
The MAX5033 delivers up to 500mA output current. The
output current may be limited by the maximum power
dissipation capability of the package. External shutdown is included, featuring 10μA (typ) shutdown current. The
MAX5033A/B/C versions have fixed output voltages of
3.3V, 5V, and 12V, respectively, while the MAX5033D fea-
tures an adjustable output voltage, from 1.25V to 13.2V.
The MAX5033 is available in space-saving 8-pin SO and
8-pin plastic DIP packages and operates over the auto-
motive (-40°C to +125°C) temperature range.
Applications●Consumer Electronics●Industrial●Distributed Power
Features●Wide 7.5V to 76V Input Voltage Range●Fixed (3.3V, 5V, 12V) and Adjustable (1.25V to
13.2V) Voltage Versions●500mA Output Current●Efficiency Up to 94%●Internal 0.4Ω High-Side DMOS FET●270μA Quiescent Current at No Load, 10μA
Shutdown Current●Internal Frequency Compensation●Fixed 125kHz Switching Frequency●Thermal Shutdown and Short-Circuit Current Limit●8-Pin SO and PDIP Packages
This product is available in both leaded(Pb) and lead(Pb)-free
packages. To order the lead(Pb)-free package, add a + after
the part number.
PARTTEMP RANGEPIN-
PACKAGE
OUTPUT
VOLTAGE (V)MAX5033AUSA0°C to +85°C8 SO
3.3MAX5033AUPA0°C to +85°C8 PDIP
MAX5033AASA-40°C to +125°C8 SO
MAX5033BUSA0°C to +85°C8 SO
5.0MAX5033BUPA0°C to +85°C8 PDIP
MAX5033BASA-40°C to +125°C8 SO
MAX5033CUSA0°C to +85°C8 SOMAX5033CUPA0°C to +85°C8 PDIP
MAX5033CASA-40°C to +125°C8 SO
MAX5033DUSA0°C to +85°C8 SO
ADJMAX5033DUPA0°C to +85°C8 PDIP
MAX5033DASA-40°C to +125°C8 SO
MAX5033GND
BST
VIN
SGND
50SQ100
220µHVOUT
5V, 0.5A
VIN
7.5V TO 76V
47µF
0.1µF
0.1µF
33µF
OFF
ON/OFF
BST
SGND
VIN
GND
ON/OFF
MAX5033
SO/PDIP
Pin Coniguration
MAX5033500mA, 76V, High-Efficiency, MAXPower
Step-Down DC-DC Converter
Typical Application Circuit
Ordering Information
EVALUATION KIT AVAILABLE
(Voltages referenced to GND, unless otherwise specified.)
VIN .........................................................................-0.3V to +80VSGND ....................................................................-0.3V to +0.3VLX.................................................................-0.8V to (VIN + 0.3V)
BST...............................................................-0.3V to (VIN + 10V)
BST (transient < 100ns)................................-0.3V to (VIN + 15V)BST to LX................................................................-0.3V to +10VBST to LX (transient < 100ns) ................................-0.3V to +15VON/OFF ..................................................................-0.3V to +80V
VD...........................................................................-0.3V to +12V
FB
MAX5033A/MAX5033B/MAX5033C...................-0.3V to +15V
MAX5033D.........................................................-0.3V to +12V
VOUT Short-Circuit Duration (VIN ≤ 40V).....................Indefinite
VD Short-Circuit Duration..............................................Indefinite
Continuous Power Dissipation (TA = +70°C)
8-Pin PDIP (derate 9.1mW/°C above +70°C)..............727mW
8-Pin SO (derate 5.9mW/°C above +70°C)..................471mW
Operating Temperature Range
MAX5033_U_ _...................................................0°C to +85°C
MAX5033_A_ _..............................................-40°C to +125°C
Storage Temperature Range.............................-65°C to +150°C
Junction Temperature.......................................................+150°CLead Temperature (soldering, 10s)...................................+300°C
Soldering Temperature (reflow) SO, PDIP Lead(Pb)-free...............................................+260°C
SO, PDIP Containing lead (Pb)....................................+240°C
(VIN = +12V, VON/OFF = +12V, IOUT = 0, TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C. See the
Typical Operating Circuit.)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSInput Voltage RangeVIN
MAX5033A7.576.0MAX5033B7.576.0
MAX5033C1576
MAX5033D7.576.0
Undervoltage LockoutUVLO5.2V
Output VoltageVOUT
MAX5033A, VIN = 7.5V to 76V,
IOUT = 20mA to 500mA3.1853.33.415MAX5033B, VIN = 7.5V to 76V,
IOUT = 20mA to 500mA4.855.05.15
MAX5033C, VIN = 15V to 76V,
IOUT = 20mA to 500mA11.641212.36
Feedback VoltageVFBVIN = 7.5V to 76V, MAX5033D1.1921.2211.250V
Eficiencyη
VIN = 12V, ILOAD = 500mA, MAX5033A86
VIN = 12V, ILOAD = 500mA, MAX5033B90
VIN = 24V, ILOAD = 500mA, MAX5033C94
VIN = 12V, VOUT = 5V, ILOAD = 500mA,
MAX5033D90
Quiescent Supply CurrentIQ
VFB = 3.5V, VIN = 7.5V to 76V, MAX5033A270440VFB = 5.5V, VIN = 7.5V to 76V, MAX5033B270440
VFB = 13V, VIN = 15V to 76V, MAX5033C270440
VFB = 1.3V, MAX5033D270440
Shutdown CurrentISHDNVON/OFF = 0V, VIN = 7.5V to 76V1045µA
MAX5033500mA, 76V, High-Eficiency, MAXPower Step-Down DC-DC Converter
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 (MAX5033_U_ _)
(VIN = +12V, VON/OFF = +12V, IOUT = 0, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C. See the
Typical Operating Circuit.) (Note 2)
(VIN = +12V, VON/OFF = +12V, IOUT = 0, TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C. See the
Typical Operating Circuit.)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSSwitch On-ResistanceRDS(ON)ISWITCH = 500mA0.40.80Ω
PFM ThresholdIPFMMinimum switch current in any cycle356595mA
FB Input Bias CurrentIBMAX5033D-150+0.01+150nA
ON/OFF CONTROL INPUTON/OFF Input-Voltage ThresholdVON/OFFRising trip point1.531.691.85V
ON/OFF Input-Voltage HysteresisVHYST100mV
ON/OFF Input CurrentION/OFFVON/OFF = 0V to VIN10150nA
ON/OFF Operating Voltage RangeVON/OFF76V
OSCILLATOROscillator FrequencyfOSC109125135kHz
Maximum Duty CycleDMAXMAX5033D95%
VOLTAGE REGULATORRegulator Output VoltageVDVIN = 8.5V to 76V, IL = 0mA6.97.88.8V
Dropout Voltage7.5V ≤ VIN ≤ 8.5V, IL = 1mA2.0V
Load RegulationΔVD/ΔIVD0 to 5mA150Ω
PACKAGE THERMAL CHARACTERISTICSThermal Resistance
(Junction to Ambient)θJASO package (JEDEC 51)170°C/WDIP package (JEDEC 51)110
THERMAL SHUTDOWNThermal-Shutdown Junction
TemperatureTSH+160°C
Thermal-Shutdown HysteresisTHYST20°C
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSInput Voltage RangeVIN
MAX5033A7.576.0MAX5033B7.576.0
MAX5033C1576
MAX5033D7.576.0
Undervoltage LockoutUVLO5.2V
Output VoltageVOUT
MAX5033A, VIN = 7.5V to 76V,
IOUT = 20mA to 500mA3.1853.33.415MAX5033B, VIN = 7.5V to 76V,
IOUT = 20mA to 500mA4.8255.05.175
MAX5033C, VIN = 15V to 76V,
MAX5033500mA, 76V, High-Eficiency, MAXPower Step-Down DC-DC Converter
Electrical Characteristics (MAX5033_A_ _)
Electrical Characteristics (MAX5033_U_ _) (continued)
(VIN = +12V, VON/OFF = +12V, IOUT = 0, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C. See the
Typical Operating Circuit.) (Note 2)
Note 1: Switch current at which the current limit is activated.
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSFeedback VoltageVFBVIN = 7.5V to 76V, MAX5033D1.1921.2211.250V
Eficiencyη
VIN = 12V, ILOAD = 500mA, MAX5033A86
VIN = 12V, ILOAD = 500mA, MAX5033B90
VIN = 24V, ILOAD = 500mA, MAX5033C94
VIN = 12V, VOUT = 5V, ILOAD = 500mA,
MAX5033D90
Quiescent Supply CurrentIQ
VFB = 3.5V, VIN = 7.5V to 76V, MAX5033A270440VFB = 5.5V, VIN = 7.5V to 76V, MAX5033B270440
VFB = 13V, VIN = 15V to 76V, MAX5033C270440
VFB = 1.3V, MAX5033D270440
Shutdown CurrentISHDNVON/OFF = 0V, VIN = 7.5V to 76V1045µA
Peak Switch Current LimitILIM(Note 1)0.951.52.1A
Switch Leakage CurrentIOLVIN = 76V, VON/OFF = 0V, VLX = 0V1µA
Switch On-ResistanceRDS(ON)ISWITCH = 500mA0.40.80Ω
PFM ThresholdIPFMMinimum switch current in any cycle3565110mA
FB Input Bias CurrentIBMAX5033D-150+0.01+150nA
ON/OFF CONTROL INPUTON/OFF Input-Voltage ThresholdVON/OFFRising trip point1.501.691.85V
ON/OFF Input-Voltage HysteresisVHYST100mV
ON/OFF Input CurrentION/OFFVON/OFF = 0V to VIN10150nA
ON/OFF Operating Voltage RangeVON/OFF76V
OSCILLATOROscillator FrequencyfOSC105125137kHz
Maximum Duty CycleDMAXMAX5033D95%
VOLTAGE REGULATORRegulator Output VoltageVDVIN = 8.5V to 76V, IL = 0mA6.57.89.0V
Dropout Voltage7.5V ≤ VIN ≤ 8.5V, IL = 1mA2.0V
Load RegulationΔVD/ΔIVD0 to 5mA150Ω
PACKAGE THERMAL CHARACTERISTICSThermal Resistance
(Junction to Ambient)θJASO package (JEDEC 51)170°C/WDIP package (JEDEC 51)110
THERMAL SHUTDOWNThermal-Shutdown Junction
TemperatureTSH+160°C
Thermal-Shutdown HysteresisTHYST20°C
MAX5033500mA, 76V, High-Eficiency, MAXPower Step-Down DC-DC Converter
Electrical Characteristics (MAX5033_A_ _) (continued)
(VIN = 12V, VON/OFF = 12V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C. See the Typical Operating
Circuit, if applicable.)
VOUT vs. TEMPERATURE
(MAX5033BASA, VOUT = 5V)MAX5033 toc02
TEMPERATURE (C)
OUT
(V)
IOUT = 0.1A
IOUT = 0.5A
LINE REGULATION
(MAX5033CASA, VOUT = 12V)
MAX5033 toc03
INPUT VOLTAGE (V)
OUT
(V)6070403020
IOUT = 0A
IOUT = 0.5A
LINE REGULATION
(MAX5033BASA, VOUT = 5V)MAX5033 toc04
INPUT VOLTAGE (V)
OUT
(V)5666362616
IOUT = 0A
IOUT = 0.5A
LOAD REGULATION
(MAX5033CASA, VOUT = 12V)MAX5033 toc05
ILOAD (mA)
OUT
(V)
VIN = 24V
VIN = 76V
LOAD REGULATION
(MAX5033BASA, VOUT = 5V)MAX5033 toc06
ILOAD (mA)
OUT
(V)
VIN = 7.5V, 24V
VIN = 76V
EFFICIENCY vs. LOAD CURRENT
(MAX5033BASA, VOUT = 5V)MAX5033 toc07
EFFICIENCY (%)
VIN = 7.5V
VIN = 12V
VIN = 24V
VIN = 48VVIN = 76V
VOUT vs. TEMPERATURE
(MAX5033CASA, VOUT = 12V)MAX5033 toc01
TEMPERATURE (C)
OUT
(V)
IOUT = 0.1A
IOUT = 0.5A
EFFICIENCY vs. LOAD CURRENT
(MAX5033CASA, VOUT = 12V)MAX5033 toc08
EFFICIENCY (%)
VIN = 15V
VIN = 24V
VIN = 48VVIN = 76V
OUTPUT CURRENT LIMIT
vs. TEMPERATUREMAX5033 toc09
OUTPUT CURRENT LIMIT (A)0.8
MAX5033BASA
5% DROP IN VOUT
MAX5033500mA, 76V, High-Eficiency, MAXPower Step-Down DC-DC Converter
Typical Operating Characteristics
(VIN = 12V, VON/OFF = 12V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C. See the Typical Operating
Circuit, if applicable.)
OUTPUT CURRENT LIMIT
vs. INPUT VOLTAGEMAX5033 toc10
INPUT VOLTAGE (V)
OUTPUT CURRENT LIMIT (A)5646362616
MAX5033BASA
VOUT = 5V
5% DROP IN VOUT
QUIESCENT SUPPLY CURRENT
vs. TEMPERATUREMAX5033 toc11
TEMPERATURE (°C)
QUIESCENT SUPPLY CURRENT (µA)
QUIESCENT SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX5033 toc12
INPUT VOLTAGE (V)
QUIESCENT SUPPLY CURRENT (µA)
SHUTDOWN CURRENT
vs. TEMPERATURE
MAX5033 toc13
TEMPERATURE (C)
SHUTDOWN CURRENT (µA)5
SHUTDOWN CURRENT
vs. INPUT VOLTAGE
MAX5033 toc14
INPUT VOLTAGE (V)
SHUTDOWN CURRENT (µA)54626616365676
OUTPUT VOLTAGE
vs. INPUT VOLTAGEMAX5033 toc15
VIN (V)
OUT
(V)96315
MAX5033CASA
VOUT = 12V
VON/OFF = VIN
IOUT = 0.3A
IOUT = 0.5A
MAX5033BASA
LOAD-TRANSIENT RESPONSEMAX5033 toc16
VOUT = 5V
MAX5033BASA
LOAD-TRANSIENT RESPONSEMAX5033 toc17
VOUT = 5V
MAX5033BASA
LOAD-TRANSIENT RESPONSEMAX5033 toc18
VOUT = 5V
MAX5033500mA, 76V, High-Eficiency, MAXPower Step-Down DC-DC Converter
Typical Operating Characteristics (continued)
(VIN = 12V, VON/OFF = 12V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C. See the Typical Operating
Circuit, if applicable.)
MAX5033BASA LX WAVEFORMSMAX5033 toc19
4ms/div
A: SWITCH VOLTAGE (LX PIN) 20V/div, VIN = 48V
B: INDUCTOR CURRENT, 200mA/div, (IOUT = 500mA)
MAX5033BASA LX WAVEFORMSMAX5033 toc20
4µs/div
A: SWITCH VOLTAGE, 20V/div, VIN = 48V
B: INDUCTOR CURRENT, 100mA/div (IOUT = 30mA)
MAX5033BASA LX WAVEFORMSMAX5033 toc21
4µs/div
A: SWITCH VOLTAGE (LX PIN), 20V/div, VIN = 48V
B: INDUCTOR CURRENT, 100mA/div (IOUT = 0)
MAX5033BASA STARTUP WAVEFORM
(IO = 0)MAX5033 toc22
1ms/div
A: VON/OFF, 2V/div
B: VOUT, 2V/div
MAX5033BASA STARTUP WAVEFORM
(IO = 0.5A)MAX5033 toc23
1ms/div
A: VON/OFF, 2V/div
B: VOUT, 2V/div
PEAK SWITCH CURRENT LIMIT
vs. INPUT VOLTAGEMAX5033 toc24
INPUT VOLTAGE (V)
PEAK SWITCH CURRENT LIMIT (A)6646362616
MAX5033BASA
VOUT = 5V
5% DROP IN VOUT
MAX5033500mA, 76V, High-Eficiency, MAXPower Step-Down DC-DC Converter
Typical Operating Characteristics (continued)
PINNAMEFUNCTIONBSTBoost Capacitor Connection. Connect a 0.1μF ceramic capacitor from BST to LX.VDInternal Regulator Output. Bypass VD to GND with a 0.1μF ceramic capacitor.SGNDInternal Connection. SGND must be connected to GND.FBOutput Sense Feedback Connection. For ixed output voltage (MAX5033A, MAX5033B, MAX5033C),
connect FB to VOUT. For adjustable output voltage (MAX5033D), use an external resistive voltage-
divider to set VOUT. VFB regulating set point is 1.22V.ON/OFFShutdown Control Input. Pull ON/OFF low to put the device in shutdown mode. Drive ON/OFF high
for normal operation.GNDGround.VINInput Voltage. Bypass VIN to GND with a low-ESR capacitor as close to the device as possible.LXSource Connection of Internal High-Side Switch.
ENABLE
BST
VINON/OFF
VREF
REGULATOR
(FOR DRIVER)
REGULATOR
(FOR ANALOG)
OSC
RAMP
HIGH-SIDE
CURRENT
SENSE
IREF-PFM
IREF-LIM
CPFM
1.69V
CILIM
VREFEAMP
CONTROL
LOGIC
CPWM
GND
CLK
SGND
MAX5033TYPE 3
COMPENSATIONTHERMAL
SHUTDOWN
RAMP
MAX5033500mA, 76V, High-Eficiency, MAXPower Step-Down DC-DC Converter
Pin Description
Simpliied Block Diagram
Detailed DescriptionThe MAX5033 step-down DC-DC converter operates from a 7.5V to 76V input voltage range. A unique volt-
age- mode control scheme with voltage feed-forward
and an internal switching DMOS FET provides high
efficiency over a wide input voltage range. This pulse-
width modulated converter operates at a fixed 125kHz switching frequency. The device also features automatic pulse-skipping mode to provide low quiescent current and
high efficiency at light loads. Under no load, the MAX5033 consumes only 270μA, and in shutdown mode, consumes only 10μA. The MAX5033 also features undervoltage
lockout, hiccup-mode output shortcircuit protection, and
thermal shutdown.
Shutdown ModeDrive ON/OFF to ground to shut down the MAX5033.
Shutdown forces the internal power MOSFET off, turns
off all internal circuitry, and reduces the VIN supply cur-rent to 10μA (typ). The ON/OFF rising threshold is 1.69V (typ). Before any operation begins, the voltage at ON/OFF must exceed 1.69V (typ). The ON/OFF input has 100mV
hysteresis.
Undervoltage Lockout (UVLO)Use the ON/OFF function to program the UVLO threshold
at the input. Connect a resistive voltage-divider from VIN to GND with the center node to ON/OFF as shown in
Figure 1. Calculate the threshold value by using the fol-
lowing formula:
UVLO(TH)V1 1.85VR2=+×
The minimum recommended VUVLO(TH) is 6.5V, 7.5V,
and 13V for the output voltages of 3.3V, 5V, and 12V,
respectively. The recommended value for R2 is less than 1MΩ.
If the external UVLO threshold-setting divider is not used,
an internal undervoltage-lockout feature monitors the
supply voltage at VIN and allows operation to start when
VIN rises above 5.2V (typ). This feature can be used only
when VIN rise time is faster than 2ms. For slower VIN rise time, use the resistive divider at ON/OFF.
Boost High-Side Gate Drive (BST)Connect a flying bootstrap capacitor between LX and
BST to provide the gate-drive voltage to the high-side
n-channel DMOS switch. The capacitor is alternately
charged from the internally regulated output-voltage
On startup, an internal low-side switch connects LX to
ground and charges the BST capacitor to VD. Once the
BST capacitor is charged, the internal low-side switch is
turned off and the BST capacitor voltage provides the
necessary enhancement voltage to turn on the high-side
switch.
Thermal-Overload ProtectionThe MAX5033 features integrated thermal-overload pro-
tection. Thermal-overload protection limits total power dis-
sipation in the device, and protects the device in the event
of a fault condition. When the die temperature exceeds
+160°C, an internal thermal sensor signals the shutdown
logic, turning off the internal power MOSFET and allow-
ing the IC to cool. The thermal sensor turns the internal
power MOSFET back on after the IC’s die temperature
cools down to +140°C, resulting in a pulsed output under
continuous thermaloverload conditions.
Applications Information
Setting the Output VoltageThe MAX5033A/B/C have preset output voltages of 3.3V,
5.0V, and 12V, respectively. Connect FB to the preset
output voltage (see the Typical Operating Circuit).
The MAX5033D offers an adjustable output voltage. Set
the output voltage with a resistive voltage-divider connect-
ed from the circuit’s output to ground (Figure 1). Connect
the center node of the divider to FB. Choose R4 less than 15kΩ, then calculate R3 as follows:
OUT(V1.22)R3R41.22−=×
MAX5033DGND
BSTVIN
SGND
50SQ100
220µH
VOUT
5V, 0.5A
VIN
7.5V TO 76V
47µF
0.1µF
0.1µF
COUT
33µFR3
41.2kΩ
13.3kΩ
ON/OFF
MAX5033500mA, 76V, High-Eficiency, MAXPower Step-Down DC-DC Converter
