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MAX17020ETJ+-MAX17020ETJ+T
Dual Quick-PWM Step-Down Controller with Low-Power LDO, RTC Regulator
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
Ordering Information19-4118; Rev 2; 2/09
General DescriptionThe MAX17020 is a dual Quick-PWM™ step-down
power-supply (SMPS) controller with synchronous rec-
tification, intended for main 5V/3.3V or I/O 1.5V/1.05V
power generation in battery-powered systems. Low-
side MOSFET sensing provides a simple low-cost,
highly efficient current sense for valley current-limit
protection. Combined with the output overvoltage and
undervoltage protection features, this current limit
ensures robust output supplies.
The 5V/3.3V or 1.5V/1.05V SMPS outputs can save
power by operatingin pulse-skipping mode or in ultra-
sonic mode to avoid audible noise. Ultrasonic mode
forces the controller to maintain switching frequencies
greater than 20kHz at light loads.
An internal 100mA linear regulator can be used to
either generate the 5V bias needed for power-up or
other lower power “always-on” suspend supplies. An
independent bypass input allows automatic bypassing
of the linear regulator when the SMPS is active.
This main controller also includes a secondary feed-
back input that triggers an ultrasonic pulse (DL1 turned
on) if the SECFB voltage drops below its threshold volt-
age. This refreshes an external charge pump driven by
DL1 without overcharging the output voltage.
The device includes independent shutdown controls to
simplify power-up and power-down sequencing. To
prevent current surges at startup, the internal voltage
target is slowly ramped up from zero to the final target
over a 1ms period. To prevent the output from ringing
below ground in shutdown, the internal voltage target
is ramped down from its previous value to zero over a
1ms period. Two independent power-good outputs
simplify the interface with external controllers.
The MAX17020 is a pin-for-pin replacement of the
MAX8778.
Features
Applications+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
PARTTEMP RANGEPIN-PACKAGEAX 17020E TJ+ -40°C to +85°C32 TQFN
Dual Quick-PWM
Internal 100mA 5V or Adjustable Linear Regulator
Independent LDO Bypass Input
Internal Boost Diodes
Secondary Feedback Input Maintains Charge Pump
3.3V 5mA RTC Power (Always On)
OUT1: 5V or 1.5V Fixed or 0.7V Adjustable
Feedback
OUT2: 3.3V or 1.05V Fixed or Dynamic Adjustable
Dynamic 0V to 2V REFIN2 Input on Second SMPS
2V ±1% 50µA Reference
6V to 24V Input Range (28V max)
Ultrasonic Mode
Independent SMPS and LDO Enable Controls
Independent SMPS Power-Good Outputs
Minimal Component CountNotebook Computers
Main System Supply (5V and 3.3V Supplies)
I/O System Supply (1.5V and 1.05V Supplies)
Graphic Cards
DDR1, DDR2, DDR3 Power Supplies
Game Consoles
Low-Power I/O and Chipset Supplies
Two-to-Four Li+ Cell Battery-Powered Devices
PDAs and Mobile Communicators
Telecommunication
MAX17020
THIN QFN (T3255-4)
5mm x 5mmTOP VIEW
A "+" SIGN FIRST-PIN INDICATOR DENOTES A LEAD-FREE PACKAGE.
TON
ONLDO
LDO
REF
DL2AGNDSECFBBST2V
DL1
PGOOD2672422201918
SKIP
OUT2
ON1
PGOOD1
ILIM1
FB1
PGND10ILIM2OUT19REFIN2+BYP
ON215DH1DH216LX1
LDOREFIN
BST1
LX2
Pin Configuration
EVALUATION KIT
AVAILABLE
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(Circuit of Figure 1, no load on LDO, RTC, OUT1, OUT2, and REF, VIN= 12V, VDD= VCC= VSECFB= 5V, VREFIN2= 1.0V, BYP =
LDOREFIN = GND, ONLDO = IN, ON1 = ON2 = VCC, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
(Note 3)
Stresses 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.
IN, ONLDO to GND................................................-0.3V to +28V
VDD, VCCto GND.....................................................-0.3V to +6V
RTC, LDO to GND....................................................-0.3V to +6V
OUT_ to GND...........................................................-0.3V to +6V
ON1, ON2 to GND....................................................-0.3V to +6V
PGOOD_ to GND........................................-0.3V to (VCC+ 0.3V)
REF, ILIM_, TON, SKIPto GND..................-0.3V to (VCC+ 0.3V)
FB1, REFIN2, LDOREFIN to GND............................-0.3V to +6V
SECFB to GND.........................................................-0.3V to +6V
BYP to GND..............................................-0.3V to (VLDO+ 0.3V)
GND to PGND.......................................................-0.3V to +0.3V
DL_ to PGND..............................................-0.3V to (VDD+ 0.3V)
BST_ to GND..........................................................-0.3V to +34V
BST_ to VDD............................................................-0.3V to +28V
DH1 to LX1..............................................-0.3V to (VBST1+ 0.3V)
BST1 to LX1..............................................................-0.3V to +6V
DH2 to LX2..............................................-0.3V to (VBST2+ 0.3V)
BST2 to LX2..............................................................-0.3V to +6V
LDO, RTC, REF Short Circuit to GND.........................Momentary
RTC Current Continuous.....................................................+5mA
LDO Current (Internal Regulator)
Continuous..................................................................+100mA
LDO Current (Switched Over) Continuous.....................+200mA
Continuous Power Dissipation (TA= +70°C)
32-Pin 5mm x 5mm TQFN
(derate 34.5mW/°C above +70°C).................................2.76W
Operating Temperature Range...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
INPUT SUPPLIESIN Standby Supply Current IIN(STBY) VIN = 6V to 24V, ON1 = ON2 = GND,
ONLDO = VCC 85 175 µA
IN Shutdown Supply Current IIN(SHDN) VIN = 4.5V to 24V,
ON1 = ON2 = ONLDO = GND 50 70 µA
IN Supply Current IIN
ON1 = ON2 = REFIN2 = VCC,
SKIP = FB1 = GND,
VOUT2 = 3.5V, VOUT1 = 5.3V
0.1 0.2 mA
VCC Supply Current ICC
ON1 = ON2 = REFIN2 = VCC,
SKIP = FB1 = GND,
VOUT2 = 3.5V, VOUT1 = 5.3V
1.0 1.5 mA
PWM CONTROLLERS5V preset output: FB1 = GND,
VIN = 12V, SKIP = VCC4.95 5.00 5.05
VOUT1
1.5V preset output: FB1 = VCC (5V),
VIN = 12V, SKIP = VCC1.485 1.50 1.515 OUT1 Output Voltage Accuracy
(Note 1)
VFB1Adjustable feedback output,
VIN = 12V, SKIP = VCC0.693 0.700 0.707
OUT1 Voltage Adjust Range 0.7 5.5 V
Low 0.04 0.110
FB1 Dual-Mode™ Threshold
Voltage Levels High VCC -
1.6V
VCC -
0.7V
FB1 Input Bias Current IFB1 VFB1 = 0.8V, TA = +25°C -0.2 +0.2 µA
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
ELECTRICAL CHARACTERISTICS (continued)(Circuit of Figure 1, no load on LDO, RTC, OUT1, OUT2, and REF, VIN= 12V, VDD= VCC= VSECFB= 5V, VREFIN2= 1.0V, BYP =
LDOREFIN = GND, ONLDO = IN, ON1 = ON2 = VCC, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
(Note 3)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS3.3V preset output: REFIN2 = VCC (5V),
VIN = 12V, SKIP = VCC3.267 3.30 3.333
1.05V preset output: REFIN2 = RTC (3.3V),
VIN = 12V, SKIP = VCC1.040 1.050 1.060 OUT2 Output Voltage Accuracy
(Note 1) VOUT2
Tracking output: VREFIN2 = 1.0V,
VIN = 12V, SKIP = VCC0.995 1.00 1.005
OUT2 Voltage-Adjust Range 0 2 V
REFIN2 Voltage-Adjust Range 0 2 V
VREFIN2 = 2.2V, TA = +25°C -0.1 +0.1 REFIN2 Input Bias Current IREFIN2 VREFIN2 = 0, TA = +25°C -0.5 +0.1 µA
Low (REFIN2 = RTC) 2.2 3.0 REFIN2 Dual-Mode Threshold
Voltage Levels High (REFIN2 = VCC)VCC -
1.0V
VCC -
0.4V
Either SMPS, SKIP = VCC, ILOAD = 0 to 5A -0.1
Either SMPS, SKIP = REF, ILOAD = 0 to 5A -1.7 Load Regulation Error
Either SMPS, SKIP = GND, ILOAD = 0 to 5A -1.5
Line Regulation Error Either SMPS, VIN = 6V to 24V 0.005 %/V
TON = GND or REF
(400kHz) 895 1052 1209 DH1 On-Time tON1
VIN = 12V,
VOUT1 = 5.0V
(Note 2) TON = VCC (200kHz) 1895 2105 2315
ns
TON = GND (500kHz) 475 555 635
DH2 On-Time tON2
VIN = 12V,
VOUT2 = 3.3V
(Note 2)
TON = REF or VCC
(300kHz) 833 925 1017 ns
Minimum Off-Time tOFF(MIN) (Note 2) 250 400 ns
Soft-Start/Stop Slew Rate tSSRising/falling edge on ON1 or ON2 (preset) 1 ms
Soft-Start/Stop Slew Rate tSSRising/falling edge on ON2 (REFIN2 ADJ) 1 mV/µs
Dynamic REFIN2 Slew Rate tDYN Rising edge on REFIN2 8 mV/µs
Ultrasonic Operating Frequency fSW(USONIC) SKIP = open (REF) 20 27 kHz
SECFB Threshold Voltage VSECFB 1.94 2.0 2.06 V
SECFB Input Bias Current ISECFB VSECFB = 2.2V, TA = +25°C -0.2 +0.2 µA
LINEAR REGULATOR (LDO)VIN = 24V, LDOREFIN = BYP = GND,
0mA < ILDO < 100mA 4.90 5.0 5.10
VIN = 24V, LDOREFIN = VCC, BYP = GND,
0mA < ILDO < 100mA 3.23 3.3 3.37 LDO Output-Voltage Accuracy VLDO
VIN = 24V, BYP = GND, VLDOREFIN = 0.5V,
0mA < ILDO < 100mA 0.960 1.0 1.040
LDOREFIN Input Range VLDOREFIN VLDO = 2 x VLDOREFIN 0.3 2.0 V
LDOREFIN Leakage Current ILDOREFIN VLDOREFIN = 0 or 2V, TA = +25°C -0.5 +0.5 µA
LDOREFIN low threshold 0.1 0.15 0.20 LDOREFIN Dual-Mode
Threshold Voltage LDOREFIN high threshold VCC -
VCC -
VCC -
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
ELECTRICAL CHARACTERISTICS (continued)(Circuit of Figure 1, no load on LDO, RTC, OUT1, OUT2, and REF, VIN= 12V, VDD= VCC= VSECFB= 5V, VREFIN2= 1.0V, BYP =
LDOREFIN = GND, ONLDO = IN, ON1 = ON2 = VCC, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
(Note 3)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSLDO Short-Circuit CurrentIILIM(LDO)LDO = GND100260mA
LDO Regulation Reduction/
Bypass Switchover Threshold
With respect to the LDO voltage,
falling edge of BYP-11.0-8.5-6.0%
LDO Bypass Switchover
Threshold
With respect to the LDO voltage,
rising edge of BYP-6.5%
LDO Bypass Switchover
Startup TimeouttBYPRising edge of BYP to bypass gate pulled low500μs
LDO Bypass Switch ResistanceLDO to BYP, VBYP = 5V (Note 4)1.24.5Ω
Falling edge of VCC,
PWM disabled below this threshold3.84.04.3VCC Undervoltage-Lockout
(UVLO) ThresholdV U V L O( V C C )
Rising edge of VCC4.2
Thermal-Shutdown ThresholdTSHDNHysteresis = 10°C+160°C
3.3V ALWAYS-ON LINEAR REGULATOR (RTC)ON1 = ON2 = GND, VIN = 6V to 24V,
0 < IRTC < 5mA3.233.333.43
RTC Output-Voltage AccuracyVRTCON1 = ON2 = ONLDO = GND,
VIN = 6V to 24V, 0 < IRTC < 5mA3.193.47
RTC Short-Circuit CurrentIILIM(RTC)RTC = GND530mA
REFERENCE (REF)Reference VoltageVREFVCC = 4.5V to 5.5V, IREF = 01.9802.002.020V
Reference Load-Regulation ErrorΔVREFIREF = -20μA to 50μA-10+10mV
REF Lockout VoltageV R E F ( U V L O) Rising edge, 350mV (typ) hysteresis1.95V
OUT1 FAULT DETECTIONOUT1 Overvoltage Trip
ThresholdV OV P ( OU T 1) With respect to error-comparator threshold131619%
OU T1 Over voltag e Faul t- r op ag ati on D el aytOVPFB1 forced 50mV above trip threshold10μs
OUT1 Undervoltage-Protection
Trip ThresholdV U V P ( OU T 1) With respect to error-comparator threshold657075%
OUT1 Output-Undervoltage
Fault-Propagation DelaytUVP10μs
PGOOD1 Lower Trip ThresholdWith respect to error-comparator threshold,
falling edge, hysteresis = 1%-19-16-13%
PGOOD1 Propagation DelaytPGOOD1FB1 forced 50mV beyond PGOOD1 trip
threshold, falling edge10μs
PGOOD1 Output Low VoltageVFB1 = 0.56V (PGOOD1 low impedance),
ISINK = 4mA0.3V
PGOOD1 Leakage CurrentIPGOOD1VFB1 = 0.70V (PGOOD1 high impedance),
PGOOD1 forced to 5.5V, TA = +25°C1μA
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
ELECTRICAL CHARACTERISTICS (continued)(Circuit of Figure 1, no load on LDO, RTC, OUT1, OUT2, and REF, VIN= 12V, VDD= VCC= VSECFB= 5V, VREFIN2= 1.0V, BYP =
LDOREFIN = GND, ONLDO = IN, ON1 = ON2 = VCC, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
(Note 3)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
OUT2 FAULT DETECTIONPreset mode (REFIN2 = RTC or VCC): with
respect to error-comparator threshold 13 16 19 %
Dynamic transition,
SKIP = REF or VCC and OUT2 > REFIN2
VREF +
0.20 V
Tracking mode: with respect to REFIN2 voltage 170 200 230 mV
OUT2 Overvoltage Trip
Threshold VOVP(OUT2)
Minimum overvoltage threshold 0.7 V
OUT2 Overvoltage
Fault-Propagation Delay tOVP OUT2 forced 50mV above trip threshold 10 µs
Preset mode: with respect to
error-comparator threshold 65 70 75 % OUT2 Undervoltage-Protection
Trip Threshold VUVP(OUT2)
Tracking mode: with respect to REFIN2 voltage -250 -300 -350 mV
OUT2 Overvoltage
Fault-Propagation Delay tOVP OUT2 forced 50mV above trip threshold 10 µs
OUT2 Output Undervoltage
Fault-Propagation Delay tUVP OUT2 forced 50mV below trip threshold 10 µs
Dynamic REFIN2 Transition
PGOOD Blanking Threshold
Blanking initiated; REFIN2 deviation from the
internal target voltage (error-comparator
threshold); hysteresis = 5mV
±25 mV
Preset mode: with respect to error-comparator
threshold, falling edge, hysteresis = 1% -19 -16 -13 %
PGOOD2 Lower Trip Threshold Tracking mode: with respect to REFIN2
voltage, falling edge, hysteresis = 12mV -175 -150 -125 mV
PGOOD2 Propagation Delay tPGOOD2 OUT2 forced 50mV beyond PGOOD1 trip
threshold, falling edge 10 µs
PGOOD2 Output-Low Voltage VOUT2 = VREFIN2 - 150mV (PGOOD2 low
impedance), ISINK = 4mA 0.3 V
PGOOD2 Leakage Current IPGOOD2 OUT2 = REFIN2 (PGOOD2 high impedance),
PGOOD2 forced to 5.5V, TA = +25°C 1 µA
CURRENT LIMITILIM_ Adjustment Range VILIM 0.2 2.0 V
ILIM_ Current IILIM 5 µA
RILIM_ = 100k 44 50 56
RILIM_ = 200k 90 100 110 Valley Current-Limit Threshold
(Adjustable) VVALLEY VAGND - VLX_
RILIM_ = 400k 180 200 220
mV
Current-Limit Threshold
(Negative) VNEG With respect to valley current-limit threshold,
SKIP = VCC -120 %
Ultrasonic Current-Limit Threshold VNEG(US) VOUT1 = VOUT2 = VFB1 = 0.77V, VREFIN2 = 0.70V 25 mV
Current-Limit Threshold
(Zero Crossing) VZXVAGND - VLX_, SKIP = GND or OPEN/REF 3 mV
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
ELECTRICAL CHARACTERISTICS (continued)(Circuit of Figure 1, no load on LDO, RTC, OUT1, OUT2, and REF, VIN= 12V, VDD= VCC= VSECFB= 5V, VREFIN2= 1.0V, BYP =
LDOREFIN = GND, ONLDO = IN, ON1 = ON2 = VCC, TA
= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
(Note 3)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
GATE DRIVERSDH_ Gate Driver On-Resistance RDHBST1 - LX1 and BST2 - LX2 forced to 5V 1.5 3.5
DL1, DL2; high state 2.2 4.5 DL_ Gate Driver On-Resistance RDL DL1, DL2; low state 0.6 1.5
DH_ Gate Driver Source/Sink
Current IDH DH1, DH2 forced to 2.5V,
BST1 - LX1 and BST2 - LX2 forced to 5V 2 A
DL_ Gate Driver Source Current IDL
(SOURCE) DL1, DL2 forced to 2.5V 1.7 A
DL_ Gate Driver Sink Current IDL (SINK) DL1, DL2 forced to 2.5V 3.3 A
Internal BST_ Switch
On-Resistance RBST IBST_ = 10mA, VDD = 5V 5
BST_ Leakage Current IBST VBST_ = 26V, TA = +25°C,
OUT2 and FB1 above regulation threshold 0.1 5 µA
INPUTS AND OUTPUTSHigh VCC -
0.4V
REF or open 1.6 3.0 TON Input Logic Levels
Low 0.4
High (forced-PWM) VCC -
0.4V
Open (ultrasonic) 1.6 3.0 SKIP Input Logic Levels
Low (skip) 0.4
SKIP, TON Leakage Current ISKIP, ITON VSKIP = VTON = 0 or 5V, TA = +25°C -2 +2 µA
High (SMPS on) 2.4 ON_ Input Logic Levels 68mV hysteresis Low (SMPS off) 0.8 V
ON_ Leakage Current ION_ VON1 = VON2 = 0 or 5V, TA = +25°C -2 +2 µA
High (SMPS on) 2.4 ONLDO Input Logic Levels 68mV hysteresis Low (SMPS off) 0.8 V
ONLDO Leakage Current IONLDO VONLDO = 0 or 24V, TA = +25°C -1 +1 µA
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
ELECTRICAL CHARACTERISTICS(Circuit of Figure 1, no load on LDO, RTC, OUT1, OUT2, and REF, VIN= 12V, VDD= VCC= VSECFB= 5V, VREFIN2= 1.0V, BYP =
LDOREFIN = GND, ONLDO = IN, ON1 = ON2 = VCC, TA
= -40°C to +85°C, unless otherwise noted.) (Note 3)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
INPUT SUPPLIESIN Standby Supply Current IIN(STBY) VIN = 6V to 24V, ON1 = ON2 = GND,
ONLDO = VCC 200 µA
IN Shutdown Supply Current IIN(SHDN) VIN = 4.5V to 24V, ON1 = ON2 = ONLDO = GND 70 µA
IN Supply Current IINON1 = ON2 = REFIN2 = VCC,
SKIP = FB1 = GND, VOUT2 = 3.5V, VOUT1 = 5.3V 0.2 mA
VCC Supply Current ICCON1 = ON2 = REFIN2 = VCC,
SKIP = FB1 = GND, VOUT2 = 3.5V, VOUT1 = 5.3V 1.5 mA
PWM CONTROLLERS5V preset output: FB1 = GND,
VIN = 12V, SKIP = VCC4.90 5.10
VOUT1 1.5V preset output: FB1 = VCC (5V),
VIN = 12V, SKIP = VCC1.47 1.53 OUT1 Output-Voltage Accuracy
(Note 1)
VFB1Adjustable feedback output,
VIN = 12V, SKIP = VCC0.685 0.715
OUT1 Voltage-Adjust Range 0.7 5.5 V
Low 0.040 0.125 FB1 Dual-Mode Threshold
Voltage High VCC -
1.6V
VCC -
0.7V
3.3V preset output: REFIN2 = VCC(5V),
VIN = 12V, SKIP = VCC3.234 3.366
1.05V preset output: REFIN2 = RTC (3.3V),
VIN = 1.2V, SKIP = VCC1.029 1.071 OUT2 Output-Voltage Accuracy
(Note 1) VOUT2
Tracking output: VREFIN2 = 1.0V,
VIN = 12V, SKIP = VCC0.985 1.015
OUT2 Voltage-Adjust Range 0 2 V
REFIN2 Voltage-Adjust Range 0 2 V
Low (REFIN2 = RTC) 2.2 3.0 REFIN2 Dual-Mode Threshold
Voltage High (REFIN2 = VCC)VCC -
1.2V
VCC -
0.4V
TON = GND or REF
(400kHz) 895 1209 DH1 On-Time tON1 VIN = 12V,
VOUT1 = 5.0V (Note 2) TON = VCC (200kHz) 1895 2315
ns
TON = GND (500kHz) 475 635
DH2 On-Time tON2 VIN = 12V,
VOUT2 = 3.3V (Note 2) TON = REF or VCC
(300kHz) 833 1017 ns
Minimum Off-Time tOFF(MIN) (Note 2) 425 ns
Ultrasonic Operating Frequency fSW(USONIC) SKIP = open (REF) 18 kHz
SECFB Threshold Voltage VSECFB 1.92 2.08 V
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
ELECTRICAL CHARACTERISTICS (continued)(Circuit of Figure 1, no load on LDO, RTC, OUT1, OUT2, and REF, VIN= 12V, VDD= VCC= VSECFB= 5V, VREFIN2= 1.0V, BYP =
LDOREFIN = GND, ONLDO = IN, ON1 = ON2 = VCC, TA
= -40°C to +85°C, unless otherwise noted.) (Note 3)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
LINEAR REGULATOR (LDO)VIN = 24V, LDOREFIN = BYP = GND,
0mA < ILDO < 100mA 4.85 5.15
VIN = 24V, LDOREFIN = VCC, BYP = GND,
0mA < ILDO < 100mA 3.20 3.40 LDO Output-Voltage Accuracy VLDO
VIN = 24V, BYP = GND, VLDOREFIN = 0.5V,
0mA < ILDO < 100mA 0.960 1.040
LDOREFIN Input Range VLDOREFIN VLDO = 2x VLDOREFIN 0.3 2.0 V
LDOREFIN low threshold 0.10 0.25
LDOREFIN Dual-Mode
Threshold Voltage LDOREFIN high threshold VCC -
2V
VCC -
0.9V
LDO Short-Circuit Current IILIM(LDO) LDO = GND 260 mA
LDO Regulation Reduction/
Bypass Switchover Threshold Falling edge of BYP -12 -5 %
VCC Undervoltage-Lockout
Threshold VUVLO(VCC) Falling edge of VCC,
PWM disabled below this threshold 3.8 4.3 V
3.3V ALWAYS-ON LINEAR REGULATOR (RTC) ON1 = ON2 = GND, VIN = 6V to 24V,
0 < IRTC < 5mA 3.18 3.45
RTC Output-Voltage Accuracy VRTC
ON1 = ON2 = ONLDO = GND,
VIN = 6V to 24V, 0 < IRTC < 5mA 3.16 3.50
RTC Short-Circuit Current IILIM(RTC) RTC = GND 5 30 mA
REFERENCE (REF)Reference Voltage VREF VCC = 4.5V to 5.5V, IREF = 0 1.975 2.025 V
Reference Load-Regulation Error VREF IREF = -20µA to 50µA -10 +10 mV
OUT1 FAULT DETECTIONOUT1 Overvoltage Trip
Threshold VOVP(OUT1) With respect to error-comparator threshold 12 20 %
OUT1 Undervoltage-Protection
Trip Threshold VUVP(OUT1) With respect to error-comparator threshold 63 77 %
PGOOD1 Lower Trip Threshold With respect to error-comparator threshold,
falling edge, hysteresis = 1% -20 -12 %
PGOOD1 Output-Low Voltage VFB1 = 0.56V (PGOOD1 low impedance),
ISINK = 4mA 0.4 V
OUT2 FAULT DETECTIONPreset mode (REFIN2 = RTC or VCC): with
respect to error-comparator threshold 12 20 % OUT2 Overvoltage Trip
Threshold VOVP(OUT2)
Tracking mode: with respect to REFIN2 voltage 160 240 mV
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
ELECTRICAL CHARACTERISTICS (continued)(Circuit of Figure 1, no load on LDO, RTC, OUT1, OUT2, and REF, VIN= 12V, VDD= VCC= VSECFB= 5V, VREFIN2= 1.0V, BYP =
LDOREFIN = GND, ONLDO = IN, ON1 = ON2 = VCC, TA
= -40°C to +85°C, unless otherwise noted.) (Note 3)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSPreset mode: with respect to error-comparator
threshold6377%OUT2 Undervoltage-Protection
Trip ThresholdVUVP(OUT2)
Tr acki ng m od e: w i th r esp ect to RE FIN 2 vol tag e-230-370mV
Preset mode: with respect to error-comparator
threshold, falling edge, hysteresis = 1%-20-12%
PGOOD2 Lower Trip ThresholdTracking mode: with respect to REFIN2
voltage, falling edge, hysteresis = 12mV-185-115mV
PGOOD2 Output-Low VoltageVOUT2 = VREFIN2 - 150mV (PGOOD2 low
impedance), ISINK = 4mA0.4V
CURRENT LIMITILIM_ Adjustment RangeVILIM0.22.0V
RILIM_ = 100kΩ4060
RILIM_ = 200kΩ85115Valley Current-Limit Threshold
(Adjustable)VVALLEYV AGN D - V LX _
RILIM_ = 400kΩ164236
GATE DRIVERSDH_ Gate Driver On-ResistanceRDHBST1 - LX1 and BST2 - LX2 forced to 5V3.5Ω
DL1, DL2; high state4.5DL_ Gate Driver On-ResistanceRDLDL1, DL2; low state1.5Ω
INPUTS AND OUTPUTSHighVCC -
0.4V
REF or open1.63.0TON Input Logic Levels
Low0.4
High (forced-PWM)VCC -
0.4V
Open (ultrasonic)1.63.0SKIP Input Logic Levels
Low (skip)0.4
High (SMPS on)2.4ON_ Input Logic LevelsLow (SMPS off)0.8V
High (LDO on)2.4ONLDO Input Logic LevelsLow (LDO off)0.8V
Note 1:DC output accuracy specifications refer to the threshold of the error comparator. When the inductor is in continuous conduc-
tion, the MAX17020 regulates the valley of the output ripple, so the actual DC output voltage is higher than the trip level by
50% of the output ripple voltage. In discontinuous conduction (IOUT< ILOAD(SKIP)), the output voltage has a DC regulation
level higher than the error-comparator threshold by approximately 1.5% due to slope compensation.
Note 2:On-time and off-time specifications are measured from 50% point to 50% point at the DH pin with LX = PGND, VBST= 5V,
and a 500pF capacitor from DH to LX to simulate external MOSFET gate capacitance. Actual in-circuit times might be differ-
ent due to MOSFET switching speeds.
Note 3:Limits are 100% production tested at TA= +25°C. Maximum and minimum limits over temperature are guaranteed by design
and characterization.
Note 4:Specifications increased by 1Ωto account for test measurement error.
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
5V OUTPUT EFFICIENCY
vs. LOAD CURRENTMAX17020 toc01
LOAD CURRENT (A)
EFFICIENCY (%)0.1
20V
12V
SKIP MODE
PWM MODE
5V OUTPUT EFFICIENCY
vs. LOAD CURRENTMAX17020 toc02
LOAD CURRENT (A)
EFFICIENCY (%)0.1
SKIP MODE
PWM MODE
ULTRASONIC
MODE
12V
3.3V OUTPUT EFFICIENCY
vs. LOAD CURRENTMAX17020 toc03
LOAD CURRENT (A)
EFFICIENCY (%)0.1
20V
12V
5V SMPS ENABLED
SKIP MODE
PWM MODE
3.3V OUTPUT EFFICIENCY
vs. LOAD CURRENTMAX17020 toc04
LOAD CURRENT (A)
EFFICIENCY (%)0.1
SKIP MODE
5V SMPS ENABLED
PWM MODE
ULTRASONIC
MODE
12V
SMPS OUTPUT VOLTAGE DEVIATION
vs. LOAD CURRENTMAX17020 toc05
LOAD CURRENT (A)
OUTPUT VOLTAGE DEVIATION (%)0.1
PWM MODE
12V
LOW-NOISE
ULTRASONIC
SKIP MODE
SWITCHING FREQUENCY
vs. LOAD CURRENTMAX17020 toc06
LOAD CURRENT (A)
SWITCHING FREQUENCY (kHz)0.1
PWM MODE
LOW-NOISE
ULTRASONIC
MODE
SKIP MODE
12V
5V LDO OUTPUT VOLTAGE
vs. LOAD CURRENTMAX17020 toc07
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
3.3V RTC OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX17020 toc08
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)468
NO-LOAD INPUT SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX17020 toc09
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)20510
PWM MODE
LOW-NOISE
ULTRASONIC
SKIP MODE
Typical Operating Characteristics(Circuit of Figure 1, VIN= 12V, VDD= VCC= 5V, TON = REF, TA= +25°C, unless otherwise noted.)
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
STANDBY AND SHUTDOWN INPUT
SUPPLY CURRENT vs. INPUT VOLTAGEMAX17020 toc10
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)20510
STANDBY (ONLDO = VIN)
SHUTDOWN
(ONLDO = ON1 = ON2 = GND)
REFERENCE OFFSET
VOLTAGE DISTRIBUTIONMAX17020 toc11
2V REF OFFSET VOLTAGE (mV)
+85°C
+25°C
SAMPLE PERCENTAGE (%)
SAMPLE SIZE = 150
REFIN2 OFFSET
VOLTAGE DISTRIBUTIONMAX17020 toc12
REFIN2 OFFSET VOLTAGE (mV)
+85°C
+25°C
SAMPLE PERCENTAGE (%)-1-3135
SAMPLE SIZE = 150
100mV ILIM THRESHOLD
VOLTAGE DISTRIBUTIONMAX17020 toc13
ILIM THRESHOLD VOLTAGE (mV)
+85°C
+25°C
SAMPLE PERCENTAGE (%)9894102106110
SAMPLE SIZE = 150
LDO AND RTC POWER-UPMAX17020 toc14
200μs/div
A. INPUT SUPPLY, 5V/div
B. 5V LDO, 2V/div
12V
3.3V
2.0V
12V
C. 3.3V RTC, 2V/div
D. 2.0V REF, 1V/div
LDO AND RTC POWER REMOVALMAX17020 toc15
200μs/div
A. INPUT SUPPLY, 5V/div
B. 5V LDO, 2V/div
3.3V12V3.3V2.0V
12V
C. 3.3V RTC, 2V/div
D. 2.0V REF, 1V/div
Typical Operating Characteristics (continued)(Circuit of Figure 1, VIN= 12V, VDD= VCC= 5V, TON = REF, TA= +25°C, unless otherwise noted.)
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
5V LDO LOAD TRANSIENTMAX17020 toc16
4μs/div
A. LDO OUTPUT,
100mV/div
0.1A
B. LOAD CURRENT,
100mA/div
5V SMPS STARTUP AND SHUTDOWNMAX17020 toc17
200μs/div
A. 5V LDO OUTPUT, 0.2V/div
B. 5V SMPS OUTPUT, 2V/div
C. ON1, 5V/div
STARTUP WAVEFORMS
(SWITCHING REGULATORS)MAX17020 toc18
100μs/div
A. ON1, 2V/div
B. 5V SMPS OUTPUT,
2V/div
C. PGOOD1, 5V/div
D. INDUCTOR CURRENT,
5A/div
SHUTDOWN WAVEFORMS
(SWITCHING REGULATORS)MAX17020 toc19
200μs/div
A. ON1, 5V/div
B. 5V SMPS OUTPUT,
2V/div
C. PGOOD1, 2V/div
D. INDUCTOR CURRENT,
5A/div
5V SMPS LOAD TRANSIENT
(PWM MODE)MAX17020 toc20
40μs/div
A. LOAD CURRENT, 2A/div
B. 5V SMPS OUTPUT, 100mV/div
C. INDUCTOR CURRENT, 2A/div
3.1A
Typical Operating Characteristics (continued)(Circuit of Figure 1, VIN= 12V, VDD= VCC= 5V, TON = REF, TA= +25°C, unless otherwise noted.)
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
3.3V SMPS LOAD TRANSIENTMAX17020 toc21
40μs/div
A. LOAD CURRENT, 5A/div
B. 3.3V SMPS OUTPUT, 100mV/div
C. INDUCTOR CURRENT, 5A/div
3.3V
0.5A
6.5A
POWER REMOVAL
(SMPS UVLO RESPONSE)MAX17020 toc22
10ms/div
A. INPUT VOLTAGE, 5V/div
B. 5V LDO OUTPUT, 2V/div
C. 5V SMPS, 2V/div
D. PGOOD1, 5V/div
Typical Operating Characteristics (continued)(Circuit of Figure 1, VIN= 12V, VDD= VCC= 5V, TON = REF, TA= +25°C, unless otherwise noted.)
Pin Description
PINNAMEFUNCTION1 REF
2V Reference-Voltage Output. Bypass REF to AGND with a 0.1µF or greater ceramic capacitor. The
reference can source up to 50µA for external loads. Loading REF degrades output-voltage accuracy
according to the REF load-regulation error. The reference shuts down when ON1, ON2, and ONLDO are all
pulled low.
2 TON
Switching-Frequency Setting Input. Select the OUT1/OUT2 switching frequencies by connecting TON as
follows for:
High (VCC) = 200kHz/300kHz
Open (REF) = 400kHz/300kHz
GND = 400kHz/500kHz
3 VCCAnalog Supply Voltage Input. Connect VCC to the system supply voltage with a series 50 resistor, and
bypass to analog ground using a 1µF or greater ceramic capacitor.
4 ONLDO Enable Input for LDO. Drive ONLDO high to enable the linear regulator (LDO) output. Drive ONLDO low to
shut down the linear regulator output.
5 RTC
3.3V Always-On Linear Regulator Output for RTC Power. Bypass RTC with a 1µF or greater ceramic
capacitor to analog ground. RTC can source at least 5mA for external load support. RTC power-up is
required for controller operation.
6 IN
Power-Input Supply. IN powers the linear regulators (RTC and LDO) and senses the input voltage for the
Quick-PWM on-time one-shot timers. The high-side MOSFET’s on-time is inversely proportional to the input
voltage. Bypass IN with a 0.1μF or greater ceramic capacitor to PGND close to the MAX17020.
7 LDO
Linear Regulator Output. Bypass LDO with a 4.7µF or greater ceramic capacitor. LDO can source at least
100mA for external load support. LDO is powered from IN and its regulation threshold is set by LDOREFIN.
For preset 5V operation, connect LDOREFIN directly to GND. For preset 3.3V operation, connect LDOREFIN
directly to VCC. When LDO is used for 5V operation, LDO must supply VCC and VDD.
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
Pin Description (continued)
PINNAMEFUNCTION8 LDOREFIN
External Reference Input for the Linear Regulator. LDOREFIN sets the LDO regulation voltage (VLDO = 2 x
VLDOREFIN) for a 0.3V to 2V LDOREFIN range. Connect LDOREFIN to GND for a fixed 5V linear-regulator
output voltage, or connect LDOREFIN to VCC for a fixed 3.3V linear-regulator output voltage. When LDO is set
to 5V and is enabled, LDO must supply VCC and VDD.
9 BYP
Linear Regulator Bypass Input. When BYP voltage exceeds 93.5% of the LDO voltage, the controller
bypasses the LDO output to the BYP input. The bypass switch is disabled if the LDO voltage drops by 8.5%
from its nominal regulation threshold. When not being used, connect BYP to GND.
10 OUT1 Output Voltage-Sense Input for SMPS1. OUT1 is an input to the Quick-PWM on-time one-shot timer. OUT1 also
serves as the feedback input for the preset 5V (FB1 = GND) and 1.5V (FB1 = VCC) output voltage settings.
11 FB1
Adjustable Feedback Voltage-Sense Connection for SMPS1. Connect FB1 to GND for fixed 5V operation.
Connect FB1 to VCC for fixed 1.5V operation. Connect FB1 to an external resistive voltage-divider from OUT1
to analog ground to adjust the output voltage between 0.7V and 5.5V.
12 ILIM1
Valley Current-Limit Adjustment for SMPS1. The GND - LX1 current-limit threshold is 1/10 the voltage present
on ILIM1 over a 0.2V to 2V range. An internal 5µA current source allows this voltage to be set with a single
resistor between ILIM1 and analog ground.
13 PGOOD1
Open-Drain Power-Good Output for SMPS1. PGOOD1 is low when the output voltage is more than 16% (typ) below
the nominal regulation threshold, during soft-start, in shutdown, and after the fault latch has been tripped. After the
soft-start circuit has terminated, PGOOD1 becomes high impedance if the output is in regulation.
14 ON1 Enable Input for SMPS1. Drive ON1 high to enable SMPS1. Drive ON1 low to shut down SMPS1.
15 DH1 High-Side Gate-Driver Output for SMPS1. DH1 swings from LX1 to BST1.
16 LX1 Inductor Connection for SMPS1. Connect LX1 to the switched side of the inductor. LX1 is the lower supply rail
for the DH1 high-side gate driver.
17 BST1 Boost Flying-Capacitor Connection for SMPS1. Connect to an external capacitor as shown in Figure 1. An
optional resistor in series with BST1 allows the DH1 turn-on current to be adjusted.
18 DL1 Low-Side Gate-Driver Output for SMPS1. DL1 swings from PGND to VDD.
19 VDDSupply-Voltage Input for the DL_ Gate Drivers. Connect to a 5V supply. Also connect to the drain of the BST
diode switch.
20 SECFB
Secondary Feedback Input. The secondary feedback input forces the SMPS1 output into ultrasonic mode
when the SECFB voltage drops below its 2V threshold voltage. This forces DL1 and DH1 to switch, allowing
the system to refresh an external low-power charge pump being driven by DL1 (see Figure 1). Connect
SECFB to VCC to the 5V bias supply to disable secondary feedback.
21 AGND Analog Ground. Connect the backside exposed pad to AGND.
22 PGND Power Ground
23 DL2 Low-Side Gate-Driver Output for SMPS2. DL2 swings from PGND to VDD.
24 BST2 Boost Flying-Capacitor Connection for SMPS2. Connect to an external capacitor as shown in Figure 1. An
optional resistor in series with BST2 allows the DH2 turn-on current to be adjusted.
25 LX2 Inductor Connection for SMPS2. Connect LX2 to the switched side of the inductor. LX2 is the lower supply rail
for the DH2 high-side gate driver.
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC Regulator
Pin Description (continued)
PINNAMEFUNCTION26 DH2 High-Side Gate-Driver Output for SMPS2. DH2 swings from LX2 to BST2.
27 ON2 Enable Input for SMPS2. Drive ON2 high to enable SMPS2. Drive ON2 low to shut down SMPS2.
28 PGOOD2
Open-Drain Power-Good Output for SMPS2. PGOOD2 is low when the output voltage is more than 150mV
(typ) below the REFIN2 voltage or more than 16% below the preset voltage, during soft-start, in shutdown,
and when the fault latch has been tripped. After the soft-start circuit has terminated, PGOOD2 becomes high
impedance if the output is in regulation. PGOOD2 is blanked—forced high-impedance state—when a
dynamic REFIN transition is detected. SKIP
Pulse-skipping Control Input. This three-level input determines the operating mode for the switching
regulators:
High (VCC) = Forced-PWM operation
Open/REF (2V) = Ultrasonic mode
GND = Pulse-skipping mode
30 OUT2 Output Voltage-Sense Input for SMPS2. OUT2 is an input to the Quick-PWM on-time one-shot timer. OUT2
also serves as the feedback input for the preset 3.3V (REFIN2 = VCC) and 1.05V (REFIN2 = RTC).
31 ILIM2
Valley Current-Limit Adjustment for SMPS2. The GND - LX2 current-limit threshold is 1/10 the voltage present
on ILIM2 over a 0.2V to 2V range. An internal 5µA current source allows this voltage to be set with a single
resistor between ILIM2 and analog ground.
32 REFIN2
External Reference Input for SMPS2. REFIN2 sets the feedback-regulation voltage (VOUT2 = VREFIN2). The
MAX17020 includes an internal window comparator to detect when the REFIN2 voltage changes, allowing the
controller to blank PGOOD2 and the fault protection. Connect REFIN2 to RTC for fixed 1.05V operation.
Connect REFIN2 to VCC for fixed 3.3V operation. EP Exposed Pad. Connect the backside exposed pad to AGND.
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC RegulatorFigure 1. Standard Application Circuit—Main Supply
LDO
DH2
BST2
5V LDO OUTPUT
INPUT (VIN)*
7V TO 24V
5V OUTPUT
DL2
LX2
PGND
AGND
POWER-GOOD}
PGOOD1
NL1NL2
NH1NH2
CBST1
0.1μF
CBST2
0.1μF
DH1
BST1
DL1
LX1
ON1
ON2OFFON
PGOOD2
100kΩ
100kΩ
COUT1COUT2
ILIM1
OUT1
FB1
ILIM2
OUT2
REFIN2
ONLDO
RTC
VDD
VCC
PAD
3.3V OUTPUT
12V TO 15V
CHARGE
PUMP
SECFB
BYP
1μF
LDOREFIN
REF
0.1μF
TON
XOUT1/OUT2 SWITCHING FREQUENCY
OPEN (REF): 400kHz/300kHz
1.0μF
500kΩ
100kΩ
47Ω
4.7μF
10nF
0.1μF
5V SMPS OUTPUT (OUT1)
0.1μF
RILIM1RILIM2
CIN
4 x 10μF 25V
DX1
DX2
RTC SUPPLY
SKIP
POWER GROUND
ANALOG GROUND
MAX17020
10nF
*LOWER INPUT VOLTAGES REQUIRE
ADDITIONAL INPUT CAPACITANCE. IF
OPERATING NEAR DROPOUT, COMPONENT
SELECTION MUST BE CAREFULLY DONE TO
ENSURE PROPER OPERATION.
C22
0.1μF
NOTE: PLACE C22 BETWEENIN AND PGND AS CLOSE AS
POSSIBLE TO THE MAX17020.
RGND
MAX17020
Dual Quick-PWM Step-Down Controller
with Low-Power LDO, RTC RegulatorFigure 2. Functional Diagram Overview
FB1
REF
DH2
BST2
LX2
VDD
DL2
DH1
BST1
LX1
VDD
DL1
PWM1
CONTROLLER
(FIGURE 3)
PGND
FB SELECT
(PRESET vs. ADJ)
ON1
REFIN2
ON2
ILIM2
OUT2
TON
ILIM1
OUT1
POWER-GOOD
AND FAULT
PROTECTION
AUL
SKIP5V LINEAR
REGULATORLDO
GND
LDO BYPASS
CIRCUITRY
ONLDO
PGOOD1
PGOOD2
VDD
UVLO
UVLO
AUL
3.3V LINEAR
REGULATORRTC
PAD
REF
VDD
BYP
LDOREFIN
SECFB
VCC
MAX17020
PWM2
CONTROLLER
(FIGURE 3)
FB SELECT
(PRESET vs. ADJ)
POWER-GOOD
AND FAULT
PROTECTION
