MAX688CUA ,High-Accuracy / Low-Dropout Linear RegulatorsMAX687/MAX688/MAX68919-0329; Rev 0; 12/94High-Accuracy, Low-DropoutLinear Regulators_______________
MAX688CUA ,High-Accuracy / Low-Dropout Linear RegulatorsFeatures' Fixed Outputs:The MAX687/MAX688/MAX689 low-dropout linear regula-tors operate with an inp ..
MAX688CUA+ ,High-Accuracy, Low-Dropout Linear RegulatorsApplicationsMAX687ESA -40°C to +85°C 8 SOHigh-Efficiency Linear RegulatorOrdering Information conti ..
MAX688CUA-T ,High-Accuracy, Low-Dropout Linear RegulatorsFeatures♦ Fixed Outputs:The MAX687/MAX688/MAX689 low-dropout linear regula-tors operate with an inp ..
MAX688CUA-T ,High-Accuracy, Low-Dropout Linear RegulatorsELECTRICAL CHARACTERISTICS(V = 3.8V, SHDN = V (MAX688/MAX689), RB = 0Ω, C1 = 2.2μF, C2 = 10μF, C3 = ..
MAX688ESA ,High-Accuracy / Low-Dropout Linear RegulatorsGeneral Description ________
MB3800 ,Switching Regulator Controller (Low Voltage)FEATURES• Wide supply voltage operating range: 1.8 to 15 V• Low current consumption: Typically 5.5 ..
MB3800PFV ,Switching Regulator Controller (Low Voltage)FUJITSU SEMICONDUCTORDS04-27212-2EDATA SHEETASSP For Power Supply
MB3800PNF ,Switching Regulator Controller (Low Voltage)ApplicationsBIPOLARSwitching Regulator Controller(Low Voltage)MB3800n DESCRIPTIONThe MB3800 is a si ..
MB3800PNF ,Switching Regulator Controller (Low Voltage)applications incorporating a soft start function and short circuit detection function. The device h ..
MB3807A ,Power Management Switching IC (with flash memory power switching function)FUJITSU SEMICONDUCTORDS04-27602-1EDATA SHEETASSP Power SupplyBIPOLARPower Management Switching I ..
MB3813A ,Lithium Ion Battery Charger DC/DC Converter IC (High Precision with Constant-current Function)Applications (Secondary battery)Lithium Ion Battery Charger DC/DC Converter IC (High Precision with ..
MAX687CPA-MAX687ESA-MAX688CSA-MAX688CUA-MAX688ESA-MAX689CSA
High-Accuracy / Low-Dropout Linear Regulators
_______________General DescriptionThe MAX687/MAX688/MAX689 low-dropout linear regula-
tors operate with an input-to-output voltage differential lim-
ited only by an external PNP transistor. Outputs are fixed
at 3.3V (MAX687/MAX688) or 3.0V (MAX689). The only
external components required are a PNP pass transistor
and output, compensation, and bypass capacitors. Base
drive to the external transistor is at least 10mA, permitting
output currents to exceed 1A when using high-gain tran-
sistors (b > 100). Output current limiting is implemented
by limiting the external transistor’s base current. Output
voltage monitoring and shutdown functions are included.
The 3.3V MAX687 automatically shuts down whenever
the output voltage drops below 2.96V. An internal
power-fail comparator also monitors the output and pro-
vides an early warning of low output voltage before the
device shuts down. When shut down, the output is
latched off until the ON input is pulsed. Turning off the
power supply in this way prevents battery damage due
to excessive discharge or cell-reversal. Typical applica-
tions include portable telephones and other battery-pow-
ered equipment where the power supply must be
disabled when the battery voltage is low.
The MAX688 and MAX689 do not have an automatic
shutdown function, and are identical except for their
output voltages. Each device has an active-low shut-
down-control input, used to turn its output on or off at
any time. As SHDNfalls, the device enters a standby
mode before fully shutting down. When in standby, the
reference and comparators are fully operational, per-
mitting the transition from normal mode to standby
mode to occur at a precise voltage level on SHDN.
________________________ApplicationsHigh-Efficiency Linear Regulator
Battery-Powered Devices
Portable Instruments
Portable Telephones
Power Supply or Backup Supply for Memory
____________________________FeaturesFixed Outputs:
3.3V (MAX687/MAX688)
3.0V (MAX689) Directly Drives External PNP Transistor10mA Min Base-Current Drive for >1A OutputLow Dropout Voltage:
100mV Dropout at 650mA Output (FZT749)
40mV Dropout at 200mA Output (FZT749)
0.8V Dropout at 4A Output Power-Fail Output Monitors the Output VoltageAutomatic, Latched Shutdown when Output Falls Out
of Regulation (MAX687)Precision Threshold Shutdown Control
(MAX688/MAX689)Low Supply Current:
150µA Operating
<1µA Shutdown2.7V to 11.0V Supply Range8-Pin DIP/SO/µMAX Packages<2mV Line Transient with 3.4V to 3.6V InputOutput Accuracy <±2%
______________Ordering Information
Ordering Information continued at end of data sheet.
MAX687/MAX688/MAX689
High-Accuracy, Low-Dropout
Linear Regulators
________________________________________________________________Maxim Integrated Products1
__________Typical Operating Circuit
__________________Pin Configuration
Call toll free 1-800-998-8800 for free samples or literature.
MAX687/MAX688/MAX689
High-Accuracy, Low-Dropout
Linear Regulators_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VIN= 3.8V, SHDN= VIN(MAX688/MAX689), RB= 0Ω, C1 = 2.2µF, C2 = 10µF, C3 = 10nF, TA= TMINto TMAX, unless otherwise
noted. Typical values are at TA= +25°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.
Input Supply Voltage IN to GND............................................12V
Terminal Voltages to GND
PFO(MAX687)........................................-0.3V to VOUT+ 0.3V
PFO(MAX688/MAX689) ......................................-0.3V to 12V
All Remaining Pins.....................................-0.3V to VIN+ 0.3V
PFOSink Current ...............................................................10mA
PFOSource Current (MAX687)...........................................10mA
Continuous Power Dissipation (TA= +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C)............727mW
SO (derate 5.88mW/°C above +70°C).........................471mW
µMAX (derate 4.1mW/°C above +70°C)......................330mW
Operating Temperature Ranges
MAX68_C_A .......................................................0°C to +70°C
MAX68_E_A ....................................................-40°C to +85°C
Storage Temperature Range.............................-65°C to +165°C
Lead Temperature (soldering, 10sec).............................+300°C
MAX687/MAX688/MAX689
High-Accuracy, Low-Dropout
Linear Regulators
_______________________________________________________________________________________3
Note 1:Minimum VINfor regulated VOUTdepends on the characteristics of the external PNP transistor, and on the load. The refer-
ence and comparators are functional down to the minimum voltage specified, but the output may not be in regulation.
Note 2: Dropout voltage is defined as VIN- VOUTwhen VOUTis 50mV below its value at VIN= VNOM+ 1V.
Note 3:The start-up time specification is the time taken from ON or SHDNrising to BASE sinking current. VOUTrise time is longer
and is a function of load capacitance, C2, and load resistance, RL.
Note 4:Minimum load capacitance is a function of RL. Minimum C2 = 10µF for loads up to 100mA and 1µF/10mA for higher loads.
ESR of C2 should be no larger than 1/100 of RL. Guaranteed by design.
Note 5:The nominal output voltage, VNOM, is defined under the default conditions of testing: VIN= 3.8V, IBASE= 1mA, TA= TMINto TMAX.
ELECTRICAL CHARACTERISTICS (continued)(VIN= 3.8V, SHDN= VIN(MAX688/MAX689), RB= 0Ω, C1 = 2.2µF, C2 = 10µF, C3 = 10nF, TA= TMINto TMAX, unless otherwise
noted. Typical values are at TA= +25°C.)
MAX687/MAX688/MAX689
High-Accuracy, Low-Dropout
Linear Regulators_______________________________________________________________________________________
__________________________________________Typical Operating Characteristics(Circuits of Figures 1 and 2, VIN= 5V, Q1 = FZT749, TA = +25°C, unless otherwise noted.)
NUMBER OF UNITS
MAX688
OUTPUT VOLTAGE DISTRIBUTION
MAX687/9-01
OUTPUT VOLTAGE (V)
MAX687
OUTPUT VOLTAGE DISTRIBUTION
MAX687/9-02
OUTPUT VOLTAGE (V)
NUMBER OF UNITS
MAX689
OUTPUT VOLTAGE DISTRIBUTION
MAX687/9-03
OUTPUT VOLTAGE (V)
NUMBER OF UNITS0.10.20.30.40.50.60.70.80.91.0
GND CURRENT vs. DROPOUT VOLTAGEMAX687/9-7
VIN - VOUT (V)
GND CURRENT (mA)
DROPOUT VOLTAGE
vs. LOAD CURRENT
MAX687/9-05
LOAD CURRENT (mA)
- V
OUT
(V)20040060080010001200
GND CURRENT
vs. LOAD CURRENTMAX687/9-06
LOAD CURRENT (mA)
GND CURRENT (mA)1234576
GND CURRENT vs. DROPOUT VOLTAGEMAX687/9-8
VIN - VOUT (V)
GND CURRENT (mA)
NO-LOAD SUPPLY CURRENT
vs. TEMPERATURE
MAX687/9-9
TEMPERATURE (°C)
SUPPLY CURRENT (
DROPOUT VOLTAGE
vs. LOAD CURRENT
MAX687/9-5
LOAD CURRENT (mA)
VIN
- V
OUT
(V)
400800
MAX687/MAX688/MAX689
High-Accuracy, Low-Dropout
Linear Regulators
_______________________________________________________________________________________5SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX687/9-10
TEMPERATURE (°C)
SHUTDOWN SUPPLY CURRENT (
OUTPUT VOLTAGE
vs. TEMPERATURE
MAX687/9-11
TEMPERATURE (°C)
OUTPUT VOLTAGE (V)
____________________________Typical Operating Characteristics (continued)
(Circuits of Figures 1 and 2, VIN= 5V, Q1 = FZT749, TA = +25°C, unless otherwise noted.)1001k10k100k
MAX687/MAX688
RIPPLE REJECTION vs. FREQUENCYMAX687/9-16
FREQUENCY (Hz)
RIPPLE REJECTION (dB)
MAX687/MAX688/MAX689
High-Accuracy, Low-Dropout
Linear Regulators_______________________________________________________________________________________
______________________________________________________________Pin Description
_______________Detailed DescriptionThe MAX687/MAX688/MAX689 are precision low-
dropout linear regulators employing external PNP tran-
sistors to achieve a wide range of output currents at
voltages of 3.0V or 3.3V. The maximum base current
for the PNP can be limited using a resistor. Limiting the
base drive keeps high currents from being wasted
when the device is in dropout (e.g., at low input volt-
ages), and limits the regulator’s output current. The
dropout voltage is limited only by the PNP transistor’s
VCE(SAT). The Power-Fail Output (PFO) goes low when
the output voltage drops 170mV below the nominal
level.
The three devices differ in their output voltages, in their
shutdown-control functions, and in PFO’s output drive
(see Table 1).
The MAX687’s output voltage is internally monitored; a
falling VOUTis signaled by PFOgoing low. As the out-
put falls further, the MAX687 automatically enters a low-
power shutdown mode, where the base drive to the
external PNP is cut off. PFOtrips at a minimum of
110mV below the nominal VOUT, and shutdown occurs
by 2.96V. PFOis guaranteed to trip before the device
