MAX770 Fast Delivery |IC PHOENIX CO.,LIMITED

MAX770 ,5V/12V/15V or Adjustable, High-Efficiency Low-IApplicationsOrdering Information continued at end of data sheet.Positive LCD-Bias Generators*Contac ..
MAX7705CSA ,レP Power-Supply Monitor with Resetapplications with microprocessors (µPs) that have a' No External ComponentsRESET input, the MAX7705 ..
MAX7705CSA+ ,µP Power Supply Monitor with ResetApplicationsMinimum Component Count, Low-Cost __________Typical Operating CircuitProcessor Systems_ ..
MAX7705ESA+ ,µP Power Supply Monitor with ResetELECTRICAL CHARACTERISTICS(V = full range, T = T to T , unless otherwise noted.)CC A MIN MAXPARAMET ..
MAX770CPA ,5V/12V/15V or Adjustable, High-Efficiency, Low IQ, Step-Up DC-DC ControllersELECTRICAL CHARACTERISTICS(V+ = 5V, I = 0mA, T = T to T , unless otherwise noted. Typical values ar ..
MAX770CSA ,5V/12V/15V or Adjustable, High-Efficiency, Low IQ, Step-Up DC-DC ControllersFeaturesThe MAX770–MAX773 step-up switching controllers pro-' 90% Efficiency for 10mA to 1A Load Cu ..
MB6M ,MINIATURE GLASS PASSIVATED SINGLE-PHASE BRIDGE RECTIFIERThermal Characteristics (TA = 25°C unless otherwise noted)Parameter Symbol MB2M MB4M MB6M UnitDevic ..
MB6S ,Bridge RectifiersThermal Characteristics (T = 25°C unless otherwise noted)AParameter Symbol MB2S MB4S MB6S UnitDevic ..
MB7117E , Schottky TTL 2048-Bit Bipolar Programmable Read-Only Memory
MB71A38-25 , PROGRAMMABLE SCHOTTKY 16384-BIT READ ONLY MEMORY

MAX770
5V/12V/15V or Adjustable, High-Efficiency Low-I
_______________General Description
The MAX770–MAX773 step-up switching controllers pro-
vide 90% efficiency over a 10mA to 1A load. A
unique current-limited pulse-frequency-modulation (PFM)
control scheme gives these devices the benefits of
pulse-width-modulation (PWM) converters (high efficiency
at heavy loads), while using less than 110μA of supply
current (vs. 2mA to 10mA for PWM converters).
These ICs use tiny external components. Their high
switching frequencies (up to 300kHz) allow surface-
mount magnetics of 5mm height and 9mm diameter.
The MAX770/MAX771/MAX772 accept input voltages
from 2V to 16.5V. Output voltages are preset at 5V,
(MAX770), 12V (MAX771), and 15V (MAX772); they can
also be adjusted using two resistors.
The MAX773 accepts inputs from 3V to 16.5V. For a wider
input range, it features an internal shunt regulator that
allows unlimited higher input voltages. The MAX773’s out-
put can be set to 5V, 12V, or 15V, or it can be adjusted
with two resistors.
The MAX770–MAX773 drive external N-channel MOSFET
switches, allowing them to power loads up to 15W. If less
power is required, use the MAX756/MAX757 or
MAX761/MAX762 step-up switching regulators with on-
board MOSFETs.
________________________Applications
Palmtops/Handy-Terminals
High-Efficiency DC-DC Converters
Battery-Powered Applications
Positive LCD-Bias Generators
Portable Communicators
Flash Memory Programmers
____________________________Features90% Efficiency for 10mA to 1A Load CurrentsUp to 15W Output Power110μA Max Supply Current5μA Max Shutdown Current2V to 16.5V Input Range
(MAX770/MAX771/MAX772)Internal Shunt Regulator for High Input Voltages
(MAX773)Preset or Adjustable Output Voltages
MAX770: 5V or Adjustable
MAX771: 12V or Adjustable
MAX772: 15V or Adjustable
MAX773: 5V, 12V, 15V, or AdjustableCurrent-Limited PFM Control Scheme300kHz Switching Frequency
______________Ordering Information
Ordering Information continued at end of data sheet.
*Contact factory for dice specifications.
**Contact factory for availability and processing to MIL-STD-883B.V/12V/15V or Adjustable, High-Efficiency,
Low IQ, Step-Up DC-DC Controllers
GND
AGND
REFSHDN
EXT
MAX770
MAX771
MAX772
DIP/SO
_________________Pin ConfigurationsAGNDGNDV+
EXTN
REF
SHDNON/OFF
OUTPUT12V
INPUT 2V TO VOUT
MAX771
__________Typical Operating Circuit
PARTTEMP. RANGEPIN-PACKAGE
MAX770CPA0°C to +70°CPlastic DIP
MAX770CSA0°C to +70°C8 SO
MAX770C/D0°C to +70°CDice*
MAX770EPA-40°C to +85°C8 Plastic DIP
MAX770ESA-40°C to +85°C8 SO
MAX770MJA-55°C to +125°C8 CERDIP**
TOP VIEW
Pin Configurations continued at end of data sheet.
19-0202; Rev 2; 11/96
EVALUATION KIT MANUAL
FOLLOWS DATA SHEET
V/12V/15V or Adjustable, High-Efficiency, Low IQ, Step-Up DC-DC Controllers
ABSOLUTE MAXIMUM RATINGS
Supply Voltages
V+ to GND.............................................................-0.3V to 17V
V+ to SGND.............................................................-0.3V to 7V
SGND........................................................-0.3V to (V+ + 0.3V)
EXT, CS, REF, LBO, LBI, SHDN, FB.............-0.3V to (V+ + 0.3V)
EXTH, EXTL..................................................-0.3V to (V+ + 0.3V)
V5, V12, V15.............................................................-0.3V to 17V
GND to AGND.........................................................0.1V to -0.1V
ISGND..................................................................................50mA
Continuous Power Dissipation (TA= +70°C)
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C)....727mW
8-Pin SO (derate 5.88mW/°C above +70°C)................471mW
8-Pin CERDIP (derate 8.00mW/°C above +70°C)........640mW
14-Pin Plastic DIP
(derate 10.00mW/°C above +70°C).............................800mW
14-Pin SO (derate 8.33mW/°C above +70°C)..............667mW
14-Pin CERDIP (derate9.09mW/°C above +70°C)......727mW
Operating Temperature Ranges
MAX77_C__........................................................0°C to +70°C
MAX77_E__......................................................-40°C to +85°C
MAX77_MJ_...................................................-55°C to +125°C
Junction Temperatures
MAX77_C__/E__..........................................................+150°C
MAX77_MJ_..................................................................+175°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C
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.
ELECTRICAL CHARACTERISTICS
(V+ = 5V, ILOAD= 0mA, TA= TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
Supply Current85110mA
Standby Current25mA
Output Voltage (Note 1)
V+ = 2.0V to 5.0V, over full load range4.805.05.20 V+ = 2.0V to 12.0V, over full load range11.5212.012.48
V+ = 2.0V to 15.0V, over full load range14.40 15.015.60
Figure 2a, V+ = 2.7V to 4.5V,
ILOAD= 700mA, VOUT= 5V5mV/V
Figure 2a, V+ = 3V, ILOAD= 30mA to 1A,
VOUT= 5V20mV/A
Maximum Switch On-TimetON(max)121620ms
Minimum Switch Off-TimetOFF(min)1.82.32.8ms
Efficiency87%
Reference VoltageVREFIREF = 0mA
MAX77_C1.47001.51.5300MAX77_E1.46251.51.5375
MAX77_M1.45501.51.5450
Output Voltage Line Regulation
(Note 2)
Output Voltage Load Regulation
(Note 2)
V+ = 4V, ILOAD=500mA, VOUT= 5V
V+ = 10.0V, SHDN ‡1.6V (shutdown)
V+ = 16.5V, SHDN ‡1.6V (shutdown)
V+ = 16.5V, SHDN = 0V (normal operation)
Minimum Start-Up VoltageMAX770/MAX771/MAX7721.82.0V
MAX770–772 (internal feedback resistors)2.016.5
MAX770–772C/E (external resistors)3.016.5
MAX770–772MJA (external resistors)3.116.5
MAX773C/E3.016.5
MAX773MJD3.116.5
Input Voltage RangeV
V/12V/15V or Adjustable, High-Efficiency, Low IQ, Step-Up DC-DC Controllers
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V, ILOAD= 0mA, TA= TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
PARAMETERSSYMBOLCONDITIONSMINTYPMAXUNITS
REF Load Regulation0mA ≤IREF≤100mAMAX77_C/E410mV
MAX77_M415
REF Line Regulation3V ≤V+ ≤16.5V40100mV/V
FB Trip-Point VoltageVFB
MAX77_C1.47001.501.5300MAX77_E1.46251.501.5375
MAX77_M1.45501.501.5450
FB Input CurrentIFB
MAX77_C±20MAX77_E±40
MAX77_M±60
SHDN Input High VoltageVIHV+ = 2.0V to 16.5V1.6V
SHDN Input Low VoltageVILMAX77_C/E, V+ = 2.0V to 16.5V 0.4V
SHDN Input Current±1mA
LBI Input CurrentMAX773, V+ = 16.5V, LBI = 1.5V±20nA
LBI HysteresisMAX77320
LBI Threshold VoltageMAX773, LBI falling
MAX77_C1.47001.501.5300MAX77_E1.46251.501.5375
MAX77_M1.45501.501.5450
LBO Leakage CurrentMAX773, V+ = 16.5V, VLBO= 16.5V0.011.00 mA
LBO Output Voltage LowVOLMAX773, V+ = 5V, LBO sinking 1mA0.10.4V
V+ = 16.5V, SHDN = 0V or V+
Current-Limit Trip LevelVCSV+ = 5V to 16.5V170200230mV
VSHUNTMAX773, ISHUNT = 1mA to 20mA,
SGND = 0V, CSHUNT= 0.1mF5.56.3V
CS Input Current0.01±1mA
EXT Rise TimeV+ = 5V, 1nF from EXT to ground (Note 3)55ns
EXT Fall TimeV+ = 5V, 1nF from EXT to ground (Note 3)55ns
Supply Voltage in
Shunt Mode
Note 1:Output voltage guaranteed using preset voltages. See Figures 7a–7d for output current capability versus input voltage.
Note 2:Output voltage line and load regulation depend on external circuit components.
Note 3:For the MAX773, EXT is EXTH and EXTL shorted together.
LBI Delay5mV overdrive2.5μs
MAX77_M, V+ = 2.0V to 16.5V 0.2
SUPPLY CURRENT vs. TEMPERATURE
TEMPERATURE (°C)
VOUT = 12V, VIN = 5V
CIRCUIT OF FIGURE 2b
BOOTSTRAPPED MODE
ENTIRE
CIRCUIT
SCHOTTKY DIODELEAKAGE EXCLUDED
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SUPPLY VOLTAGE (V)
(m
VOUT = 12V
NON-BOOTSTRAPPEDCIRCUIT OF FIGURE 2c
BOOTSTRAPPED
CIRCUIT OF
FIGURE 2b
AX770–3-08
EXT RISE/FALL TIME vs. SUPPLY VOLTAGE
V+ (V)
(nCEXT = 2200pF
CEXT = 1000pF
CEXT = 446pF
CEXT = 100pF
X770–3-09
MAX772
EFFICIENCY vs. OUTPUT CURRENT
(BOOTSTRAPPED)
OUTPUT CURRENT (A)
(%
VOUT = 15V, CIRCUIT OF FIGURE 2b
MAX772 SUBSTITUTED FOR MAX771
VIN = 12V
VIN = 9V
VIN = 6V
VIN = 5V
VIN = 3V
AX770–3-03
0.0010.011
MAX771
EFFICIENCY vs. OUTPUT CURRENT
(BOOTSTRAPPED)
OUTPUT CURRENT (A)
VIN = 6V
VIN = 5V
VIN = 3V
VIN = 9V
VOUT = 12V
CIRCUIT OF
FIGURE 2b
AX770–3-02
MAX770
EFFICIENCY vs. OUTPUT CURRENT
(BOOTSTRAPPED)
OUTPUT CURRENT (A)
(%
VIN = 3V
VIN = 3.5V
VOUT = 5V
CIRCUIT OF
FIGURE 2a
VIN = 4V
770–3-01V/12V/15V or Adjustable, High-Efficiency,
Low IQ, Step-Up DC-DC Controllers
__________________________________________Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
MAX771
EFFICIENCY vs. OUTPUT CURRENT
(NON-BOOTSTRAPPED)
OUTPUT CURRENT (A)
VIN = 9V
VIN = 6V
VIN = 5V
VOUT = 12V
CIRCUIT OF
FIGURE 2c
AX770–3-04
MAX770
LOAD CURRENT vs.
MINIMUM START-UP INPUT VOLTAGE
MINIMUM START-UP INPUT VOLTAGE (V)
ABOVE 3.4V,
THE CIRCUIT
STARTS UP
UNDER MAXIMUM
LOAD
CONDITIONS
VOUT = 5V
CIRCUIT OF
FIGURE 2a
AX770–3-05
MAX771LOAD CURRENT vs.
MINIMUM START-UP INPUT VOLTAGE
MINIMUM START-UP INPUT VOLTAGE (V)
ABOVE 3.5V
THE CIRCUIT
STARTS UP UNDER
MAXIMUM
LOAD
CONDITIONS
VOUT = 12V
CIRCUIT OF
FIGURE 2b
AX770–3-06
V/12V/15V or Adjustable, High-Efficiency, Low IQ, Step-Up DC-DC Controllers
REFERENCE OUTPUT RESISTANCE vs.
TEMPERATURE
AX770–3-10
TEMPERATURE (°C)
(W100
100µA
50µA
10µA1.502
REFERENCE vs. TEMPERATURE
AX770–3-11
TEMPERATURE (°C)
(V100-4008040120
SHUTDOWN CURRENT vs. TEMPERATURE
X770–3-12
TEMPERATURE (°C)
(µ100-4008040120
V+ = 15V
V+ = 4V
V+ = 8V
MAXIMUM SWITCH ON-TIME vs.
TEMPERATURE
TEMPERATURE (°C)
) (µ
AX770–3-13
MINIMUM SWITCH OFF-TIME vs.
TEMPERATURE
TEMPERATURE (°C)
) (µ
MAXIMUM SWITCH ON-TIME/
MINIMUM SWITCH OFF-TIME RATIO
vs. TEMPERATURE
TEMPERATURE (°C)
AX770–3-15
____________________________Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
V/12V/15V or Adjustable, High-Efficiency, Low IQ, Step-Up DC-DC Controllers
VIN = 2.9V, IOUT = 0.9A
A: EXT VOLTAGE, 5V/div
B: INDUCTOR CURRENT 1A/div
C: VOUT RIPPLE 100mV/div, AC-COUPLED
MAX770
HEAVY-LOAD SWITCHNG WAVEFORMS
20ms/div
VOUTA
ILIM
ILIM
2 B
V+ = 3V, IOUT = 165mA
A: EXT VOLTAGE, 5V/div
B: INDUCTOR CURRENT, 1A/div
C: VOUT RIPPLE 100mV/div, AC-COUPLED
MAX770
LIGHT-LOAD SWITCHING WAVEFORMS
20ms/divB
ILIM
IOUT = 0.7A
A: VIN, 2.7V TO 4.5V, 2V/div
B: VOUT RIPPLE, 100mV/div, AC-COUPLED
MAX770
LINE-TRANSIENT RESPONSE
4.5V
2.7V
2ms/div
VIN = 3V
A: LOAD CURRENT 0.5A/div (0A to 1A)
B: VOUT RIPPLE, 100mV/div, AC-COUPLED
MAX770
LOAD-TRANSIENT RESPONSE
2ms/div
____________________________Typical Operating Characteristics (continued)
(Circuit of Figure 2a, TA = +25°C, unless otherwise noted.)
V/12V/15V or Adjustable, High-Efficiency, Low IQ, Step-Up DC-DC Controllers
VIN = 3V, IOUT = 0.5A
A: SHDN, 2V/div
B: VOUT, 2V/div
MAX770
EXITING SHUTDOWN
200ms/div
______________________________________________________________Pin Description
____________________________Typical Operating Characteristics (continued)
(Circuit of Figure 2a, TA = +25°C, unless otherwise noted.)
PIN
NAMEFUNCTIONMAX773—EXTGate drive for external N-channel power transistor3V+6FB7SHDN8REF—AGNDAnalog ground9GNDHigh-current ground return for the output driver11CS1V122V5
MAX770
MAX771
MAX772
Power-supply input. Also acts as a voltage-sense point when in bootstrapped mode for the
MAX770/MAX771/MAX772, or as a shunt regulator when SGND is connected to ground for the
MAX773. Bypass to SGND with 0.1mF when using the shunt regulator.
Feedback input for adjustable-output operation. Connect to ground for fixed-output operation. Use
a resistor divider network to adjust the output voltage. See Setting the Output Voltagesection.
Active-high TTL/CMOS logic-level shutdown input. In shutdown mode, VOUTis a diode drop
below V+ (due to the DC path from V+ to the output) and the supply current drops to 5mA
maximum. Connect to ground for normal operation.
1.5V reference output that can source 100mA for external loads. Bypass to GND with 0.1mF.
The reference is disabled in shutdown.
Positive input to the current-sense amplifier. Connect the current-sense resistor between CS and GND.
Input sense point for 12V-output operation. Connect VOUTto V12 for 12V-output operation.
Leave unconnected for adjustable-output operation.
Input sense point for 5V-output operation. Connect VOUTto V5 for 5V-output operation. Leave
unconnected for adjustable-output operation.4LBO5LBIInput to the internal low-battery comparator. Tie to GND or V+ if not used.10SGNDShunt regulator ground. Leave unconnected if the shunt regulator is not used.
Low-battery output is an open-drain output that goes low when LBI is less than 1.5V. Connect to V+
through a pull-up resistor. Leave floating if not used. LBO is high impedance in shutdown mode.
V/12V/15V or Adjustable, High-Efficiency, Low IQ, Step-Up DC-DC Controllers
_______________Detailed Description
The MAX770–MAX773 are BiCMOS, step-up, switch-
mode power-supply controllers that provide preset 5V,
12V, and 15V output voltages, in addition to adjustable-
output operation. Their unique control scheme com-
bines the advantages of pulse-frequency modulation
(low supply current) and pulse-width modulation (high
efficiency with heavy loads), providing high efficiency
over a wide output current range, as well as increased
output current capability over previous PFM devices.
In addition, the external sense resistor and power
transistor allow the user to tailor the output current
capability for each application. Figure 1 shows the
MAX770–MAX773 block diagram.
The MAX770–MAX773 offer three main improvements
over prior pulse-skipping control solutions: 1) the con-
verters operate with tiny (5mm height and less than
9mm diameter) surface-mount inductors due to their
300kHz switching frequency; 2) the current-limited PFM
control scheme allows 87% efficiencies over a wide
range of load currents; and 3) the maximum supply
current is only 110μA.
The MAX773 can be configured to operate from an
internal 6V shunt regulator, allowing very high input/out-
put voltages. Its output can be configured for an
adjustable voltage or for one of three fixed voltages
(5V, 12V, or 15V), and it has a power-fail comparator for
low-battery detection.
All devices have shutdown capability, reducing the
supply current to 5μA max.
Bootstrapped/Non-Bootstrapped Modes
Figures 2 and 3 show standard application circuits for
bootstrapped and non-bootstrapped modes. In boot-
strapped mode, the IC is powered from the output
(VOUT, which is connected to V+) and the input voltage
range is 2V to VOUT. The voltage applied to the gate of
the external power transistor is switched from VOUTto
ground, providing more switch gate drive and thus
reducing the transistor’s on resistance.
In non-bootstrapped mode, the IC is powered from the
input voltage (V+) and operates with minimum supply
current. In this mode, FB is the output voltage sense
point. Since the voltage swing applied to the gate of the
external power transistor is reduced (the gate swings
from V+ to ground), the power transistor’s on resistance
increases at low input voltages. However, the supply
current is also reduced because V+ is at a lower volt-
age, and because less energy is consumed while
charging and discharging the external MOSFET’s gate
capacitance. The minimum input voltage for the
MAX770–MAX773 is 3V when using external feedback
resistors. With supply voltages below 5V, bootstrapped
mode is recommended.
Note: When using the MAX770/MAX771/MAX772 in
non-bootstrapped mode, there is no preset output
operation because V+ is also the output voltage
sense point for fixed-output operation. External
resistors must be used to set the output voltage.
Use 1% external feedback resistors when operating
in adjustable-output mode (Figures 2c, 2d, 3b, 3d, 3e)
to achieve an overall output voltage accuracy of ±5%.
The MAX773 can be operated in non-bootstrapped
mode without using external feedback resistors
because V+ does not act as the output voltage sense
point with preset-output operation. To achieve high-
est efficiency, operate in bootstrapped mode when-
ever possible.
MAX773 Shunt-Regulator Operation
The MAX773 has an internal 6V shunt regulator that
allows the device to step up from very high input
voltages (Figure 4).
PIN
NAMEFUNCTIONMAX770
MAX771
MAX772
MAX77313EXTH12EXTLLow-level gate/base drive for external power transistor. Connect to the gate of an external
N-channel MOSFET or to the base of an external NPN transistor.14V15Input sense point for 15V-output operation. Connect VOUTto V15 for 15V-output operation.
Leave unconnected for adjustable-output operation
_________________________________________________Pin Description (continued)
High-level gate/base drive for external power transistor. Connect to EXTL when using an external
N-channel MOSFET. When using an external NPN transistor, connect a resistor RBASEfrom
EXTH to the base of the NPN to set the maximum base-drive current.
Floating the shunt-regulator ground (SGND) disables
the shunt regulator. To enable it, connect SGND to
GND. The shunt regulator requires 1mA minimum cur-
rent for proper operation; the maximum current must
not exceed 20mA. The MAX773 operates in non-boot-
strapped mode when the shunt regulator is used, and
EXT swings between the 6V shunt-regulator voltage
and GND.
When using the shunt regulator, use an N-channel pow-
er FET instead of an NPN power transistor as the power
switch. Otherwise, excessive base drive will collapse
the shunt regulator.
External Power-Transistor
Control Circuitry
PFM Control Scheme
The MAX770–MAX773 use a proprietary current-limited
PFM control scheme to provide high efficiency over a
wide range of load currents. This control scheme com-
bines the ultra-low supply current of PFM converters (or
pulse skippers) with the high full-load efficiency of
PWM converters.
Unlike traditional PFM converters, the MAX770–
MAX773 use a sense resistor to control the peak induc-
tor current. They also operate with high switching V/12V/15V or Adjustable, High-Efficiency,
Low IQ, Step-Up DC-DC Controllers
EXT
CONTROL
1.5V
REFERENCETRIGS
F/FTRIG
LOW-VOLTAGE
OSCILLATOR2.5V
0.1V0.2V
ONE-SHOT
ONE-SHOT
CURRENT-SENSE
AMPLIFIER
DUAL-MODE
COMPARATOR
LBOV15V12V5FB
LBI
REF
200mV
ERROR
COMPARATOR
SHDN
SGND
EXTH
EXTL
EXT
MAX773 ONLY
MAX770
MAX771
MAX772
MAX770
MAX771
MAX772
BIAS
CIRCUITRY
MAX770–MAX773
MAX773
ONLY
Figure 1. Block Diagram
frequencies (up to 300kHz), allowing the use of tiny
external components.
As with traditional PFM converters, the power transistor
is not turned on until the voltage comparator senses
that the output is out of regulation. However, unlike tra-
ditional PFM converters, the MAX770–MAX773 switch
using the combination of a peak current limit and a pair
of one-shots that set the maximum on-time (16μs) and
minimum off-time (2.3μs); there is no oscillator. Once
off, the minimum off-time one-shot holds the switch
off for 2.3μs. After this minimum time, the switch either
1) stays off if the output is in regulation, or 2) turns on
again if the output is out of regulation.
The control circuitry allows the ICs to operate in contin-
uous-conduction mode (CCM) while maintaining high
efficiency with heavy loads. When the power switch isV/12V/15V or Adjustable, High-Efficiency,
Low IQ, Step-Up DC-DC Controllers
MAX770
VIN = 3V
REF
SHDN
AGND
GND
EXT
0.1mF
100mFL1
22mHD1
1N5817
MTP3055EL
RSENSE
75mW
300mF
0.1mF
VOUT = 5V
@ 1A
Figure 2a. 5V Preset Output, Bootstrapped Figure 2b. 12V Preset Output, Bootstrapped
Figure 2c. 12V Output, Non-Bootstrapped Figure 2d. 9V Output, Bootstrapped
MAX770
MAX771
MAX772
VIN = 5V
REF
SHDN
AGND
GND
EXT
22mHD1
1N5817
18k
200mF
0.1mF
68mF
VOUT = 12V
@ 0.5A
127k
RSENSE
100mW
0.1mF
VOUT
VREFR2 = (R1) ( -1)
VREF = 1.5V
MAX770
MAX771
MAX772
REF
SHDN
AGND
GND
EXT
47mFL1
20mHD1
1N5817
28k
100mF
0.1mF
VOUT = 9V
140k
RSENSE
0.1mF
VOUT
VREFR2 = (R1) ( -1)
VREF = 1.5V
Si9410DY
VIN = 4V
MAX771
VIN = 5V
REF
SHDN
AGND
GND
EXT
0.1mF
68mFL1
22mHD1
1N5817
Si9410DY
RSENSE
100mW
200mF
0.1mF
VOUT = 12V
@ 0.5A

Partno	Mfg	Dc	Qty	Available	Descript
MAX770		N/a	1000	avai	5V/12V/15V or Adjustable, High-Efficiency Low-I