MAX16024LTBS+ ,Battery-Backup Circuits with Regulated Output VoltageApplicationsindicates an open-drain output. The next placeholder “_” desig-Main/Backup Power for RT ..
MAX16027TP+T ,Dual-/Triple-/Quad-Voltage, Capacitor-Adjustable, Sequencing/Supervisory CircuitsApplicationsorders are available in 2.5k increments.Multivoltage SystemsPin ConfigurationsDC-DC Sup ..
MAX16029TG+ ,Dual-/Triple-/Quad-Voltage, Capacitor-Adjustable, Sequencing/Supervisory Circuitsapplications.♦ Fixed (140ms min)/Capacitor-Adjustable DelayAs the voltage at each monitored input e ..
MAX1602EEE ,Single-Channel CardBus and PCMCIA VCC/VPP Power-Switching NetworkApplicationsVCCVXVCCData LoggersVYVCCHandy-TerminalsVYVCCDocking StationsVDDPCMCIA Read/Write Drive ..
MAX1602EEE ,Single-Channel CardBus and PCMCIA VCC/VPP Power-Switching Networkapplications is supported in two ways:low-resistance 3.3V switches allow high 3.3V load cur-' Therm ..
MAX1602EEE ,Single-Channel CardBus and PCMCIA VCC/VPP Power-Switching NetworkELECTRICAL CHARACTERISTICS(VY = 3.3V, VX = 5V, 12IN = 12V, T = 0°C to +85°C, unless otherwise noted ..
MAX4287EUA ,+3V/+5V / 250MHz / SOT23 ADC Buffer Amplifiers with High-Speed Disableapplications. Space-Saving SOT23 and µMAX PackagesThe MAX4285/MAX4286 are available in space-savi ..
MAX4288EUB ,+3V/+5V, 250 MHz, SOT23 ADC buffer amplifier with high-speed disableApplicationsOrdering InformationHigh-Speed ADC DriversTEMP. PIN- SOT TOPPARTRANGE PACKAGE MARKCommu ..
MAX4289EUT+T ,1.0V Micropower, SOT23, Operational AmplifierApplications♦ Available in a Tiny 6-Pin SOT23 (3mm ✕ 3mm)Single-Cell Systems Strain GaugesPortable ..
MAX428ACSA ,Single/Dual/Quad High-Speed / Fast-Settling / High Output Current Operational AmplifierELECTRICAL CHARACTERISTICS—MAX408 (V = ±5V, T = +25°C, unless otherwise noted.)S AMAX408C MAX408ACP ..
MAX428ACSA ,Single/Dual/Quad High-Speed / Fast-Settling / High Output Current Operational AmplifierELECTRICAL CHARACTERISTICS—MAX408 (V = ±5V, T = +25°C, unless otherwise noted.)S AMAX408C MAX408ACP ..
MAX428CPA ,Single/Dual/Quad High-Speed / Fast-Settling / High Output Current Operational AmplifierApplications Ordering InformationVideo AmplifiersPART TEMP. RANGE PIN-PACKAGETest EquipmentMAX408AC ..
MAX16024LTBS+
Battery-Backup Circuits with Regulated Output Voltage
General DescriptionThe MAX16023/MAX16024 low-power battery-backup cir-
cuits with a regulated output are capable of delivering up
to 100mA output current. The MAX16023/MAX16024
include a low-dropout regulator, a microprocessor (µP)
reset circuit, and a battery switchover circuit. Additional
available features include a manual reset, a power-fail
comparator, and a battery-on indicator. These devices
reduce the number of external components to minimize
board space and improve reliability.
The MAX16023/MAX16024 are ideally suited for provid-
ing power for backing up critical memory such as static
random-access memory (SRAM) or real-time clocks
(RTCs). The regulated output is powered by VCC when it
is present and switches over to the backup power dur-
ing brownout. The MAX16023/MAX16024 accept an
input voltage from 1.53V to 5.5V and provide fixed stan-
dard output voltages of 1.2V, 1.8V, 2.5V, 3.0V, and 3.3V.
The MAX16024 offers the ability to externally set the out-
put voltage using a resistive divider. All outputs are
available with push-pull or open-drain configurations.
The MAX16023 offers a power-fail comparator for monitor-
ing an additional voltage or for providing an early power-
fail warning. Another feature includes a manual-reset input
(MAX16023/MAX16024). The MAX16024 also features
a battery-on indicator and chip-enable gating function.
The MAX16023/MAX16024 are offered in 8- and 10-pin
TDFN packages and are fully specified from -40°C to
+85°C temperature range.
ApplicationsMain/Backup Power for RTCs/SRAM
Industrial Controls
GPS Systems
Set-Top Boxes
Point-of-Sale Equipment
Portable/Battery Equipment
FeaturesSystem Monitoring for 5V, 3.3V, 3V, 2.5V, or 1.8V
Power-Supply Voltages100mA Low-Dropout RegulatorFactory-Trimmed and Adjustable Output Voltages1.53V to 5.5V Operating Voltage RangeLow-Power Consumption: 4µA (typ)Power-Fail Comparators for Monitoring Voltages
Down to 0.6VBattery-On IndicatorBattery Freshness SealOn-Board Gating of CE Signals, 1.5ns
Propagation Delay (MAX16024)Debounced Manual-Reset Input145ms (min) Reset Timeout PeriodTiny 8-Pin and 10-Pin TDFN PackagesUL®Certified to Conform to IEC 60950-1
MAX16023/MAX16024
Battery-Backup Circuits with
Regulated Output Voltage19-4249; Rev 0; 8/08
Ordering Information
PARTTEMP RANGEPIN-PACKAGE
MAX16023_TA_ _ _+T-40°C to +85°C8 TDFN-EP*
MAX16024_TB_ _ _+T-40°C to +85°C10 TDFN-EP*
The first placeholder “_” designates reset output options. A letter
“L” in this placeholder indicates a push-pull output and letter “P”
indicates an open-drain output. The next placeholder “_” desig-
nates the reset threshold (Table 1). The last two placeholders
“_ _” designate output voltage (Table 2). For the MAX16024 with
adjustable output voltage version, there are no last two place-
holders.
+Denotes a lead-free/RoHS-compliant package.
T = Tape and reel.
*EP = Exposed pad.
Pin Configurations765234
PFOGND
*EP*EP
RESETOUT
PFIMR
BATT
MAX16023987234
GNDOUTRESETCEOUT
BATT
CEIN
BATT ON
SET
MAX16024
+UL is a registered trademark of Underwriters Laboratories, Inc.
MAX16023/MAX16024
Battery-Backup Circuits with
Regulated Output Voltage
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VCC= 1.53V to 5.5V, VBATT= 3V, reset not asserted, TA= TJ= -40°C to +85°C, COUT= 10µF, unless otherwise noted. Typical val-
ues are at TA= TJ= +25°C.) (Note 2)
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.
VCC, BATT, OUT to GND..........................................-0.3V to +6V
RESET, PFO, BATT ON (all open drain)
to GND..................................................................-0.3V to +6V
RESET, PFO, BATT ON (all push-pull)
to GND .................................................-0.3V to (VOUT+ 0.3V)
PFI, CEIN, CEOUT to GND.......................-0.3V to (VOUT+ 0.3V)to GND.................................................-0.3V to (VCC+ 0.3V)
Input Current
VCC Peak Current.....................................................................1A
VCCContinuous Current...............................................250mA
BATT Peak Current.......................................................500mA
BATT Continuous Current...............................................70mA
Output Current
OUT Short Circuit to GND Duration....................................10s
RESET, BATT ON, CEOUT..............................................20mA
Continuous Power Dissipation (TA= +70°C)
8-Pin TDFN (derate 24.4mW/°C above +70°C).........1951mW
10-Pin TDFN (derate 24.4mW/°C above +70°C).......1951mW
Thermal Resistance (Note 1)
θJA (8-Pin and 10-Pin TDFN)........................................41°C/W
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
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSOperating Voltage RangeVCC, VBATT(Note 3)1.535.5V
LDO = 1.2V4.36
LDO = 1.8V4.77
LDO = 2.5V5.27.5
LDO = 3V5.58
VCC = LDO + 0.5V,
no load
LDO = 3.3V5.78
LDO = 1.2V1620
LDO = 1.8V1621
LDO = 2.5V1618.1
LDO = 3V1718.6
Supply CurrentICC
VCC = LDO + 0.5V,
IOUT = 20mA
LDO = 3.3V1719
Supply Current in Battery-Backup
ModeIBATTVCC = 0, VBATT = 3V,
no dropout, no load3.55.26µA
BATT Standby CurrentVCC > VBATT + 0.2V-0.01+0.01µA
SET Reference VoltageVSETMAX16024_TB_, VCC = 2.2V1.1441.21.272V
SET Input Leakage CurrentMAX16024_TB_, SET = 1.2V-20+20nA
Output Voltage RangeVOUTMAX16024_TB_, VCC > VOUT1.85.25V
LDO = 1.2V1.1451.21.270
LDO = 1.8V1.7041.81.900
LDO = 2.5V2.3682.52.634
LDO = 3V2.83733.165
Output Voltage AccuracyIOUT = 1mA
LDO = 3.3V3.1143.33.482
Note 1:Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to /thermal-tutorial.
MAX16023/MAX16024
Battery-Backup Circuits with
Regulated Output Voltage
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSLine RegulationVCC = (VOUT + 1V) to (VOUT + 2V),
IOUT = 1mA0.21.0%/V
Load RegulationVCC = VOUT + 1V, IOUT = 1mA to 2mA0.151.0%
LDO = 1.2V500
LDO = 1.8V200
LDO = 2.5V180
LDO = 3V150
Dropout VoltageIOUT = 50mA
(Note 4)
LDO = 3.3V150
VCC = 1.6V75Output Current LimitVCC ≥ 2V150mA
Battery Freshness Leakage
CurrentVBATT = 5.5V10nA
RESET OUTPUT (RESET)Reset ThresholdVTH(See Table 1)V
VCC Falling to Reset DelaytRDVCC falling at 10V/ms20µs
Reset Timeout PeriodtRPVCC rising145215285ms
VOUT = 3.3V, ISINK = 3.2mA, RESET asserted0.3
VOUT = 1.8V, ISINK = 1mA, RESET asserted0.3RESET Output Low VoltageVOL
VOUT = 1.2V, ISINK = 100µA, RESET asserted0.3
RESET Output High Voltage
(Push-Pull Output)VOHVCC ≥ 1.1 x VTH, ISOURCE = 100µA,
RESET deassertedVOUT - 0.3VV
RESET Output Leakage Current
(Open-Drain Output)V RESET = 5.5V, reset deasserted1µA
POWER-FAIL COMPARATOR (PFI, PFO)PFI Input ThresholdVPFTVPFI falling, 1.6V ≤ VCC ≤ 5.5V0.5700.5900.611V
PFI Input HysteresisVPFI-HYS30mV
PFI Input CurrentIPFI-1+1µA
VOUT = 1.8V, ISINK = 1mA, PFO asserted0.3PFO Output Low VoltageVOUT =1.2V, ISINK = 100µA, PFO asserted0.3V
PFO Output High Voltage
(Push-Pull Output)ISOURCE = 100µA, PFO deassertedVOUT - 0.3VV
PFO Leakage Current
(Open-Drain Output)V PFO = 5.5V, PFO deasserted1µA
PFO Delay Time(VPFI + 100mV) to (VPFI - 100mV)20µs
MANUAL RESET (MR)Input Low VoltageVIL0.3 x VCC
Input High VoltageVIH0.7 x VCCV
Pullup ResistancePullup resistance to VCC2030kΩ
Glitch Immunity100ns
MR to Reset Delay120ns
ELECTRICAL CHARACTERISTICS (continued)(VCC= 1.53V to 5.5V, VBATT= 3V, reset not asserted, TA= TJ= -40°C to +85°C, COUT= 10µF, unless otherwise noted. Typical val-
ues are at TA= TJ= +25°C.) (Note 2)
MAX16023/MAX16024
Battery-Backup Circuits with
Regulated Output Voltage
ELECTRICAL CHARACTERISTICS (continued)(VCC= 1.53V to 5.5V, VBATT= 3V, reset not asserted, TA= TJ= -40°C to +85°C, COUT= 10µF, unless otherwise noted. Typical val-
ues are at TA= TJ= +25°C.) (Note 2)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
BATTERY-ON INDICATOR (BATT ON)VOUT = 1.2V, ISINK = 100µA, BATT ON
deasserted0.3
VOUT = 1.8V, ISINK = 1mA, BATT ON
deasserted0.3Output Low VoltageVOL
VOUT = 3.3V, ISINK = 3.2mA, BATT ON
deasserted0.3
Output High Voltage
(Push-Pull Output)VOHISOURCE = 100µA, BATT ON assertedVOUT - 0.3VV
Output Leakage Current
(Open-Drain Output)VCC = 5.5V1µA
Output Short-Circuit CurrentSink current, VCC = 5V
(Note 6)60mA
CE GATING (CEIN, CEOUT)CEIN Leakage CurrentReset asserted, VCC = 0.9 x VTH or 0-1+1µA
CEIN to CEOUT ResistanceVCC = 5V, reset deasserted850Ω
CEOUT Short-Circuit CurrentReset asserted, CEOUT = 00.752mA
CEIN to CEOUT Propagation
Delay50Ω source, CLOAD = 50pF, VCC = 4.75V1.57ns
Output High VoltageVOHISOURCE = 100µA, reset assertedVOUT - 0.3VV
Reset to CEOUT Delay12µs
Note 2:All devices are 100% production tested at TA= +25°C and TA= +85°C. Limits over temperature are guaranteed by design.
Note 3:VBATTcan be 0 anytime or VCCcan go down to 0 if VBATTis active (except at startup).
Note 4:Dropout voltage is defined as (VIN- VOUT) when VOUTis 2% below the value of VOUTwhen VIN= VOUT+ 1V.
Note 5:CEIN to CEOUT resistance is tested with VCC= 5V and VCEIN= 0 or 5V.
Note 6:Use external current-limiting resistor to limit current to 20mA (max).
MAX16023/MAX16024
Battery-Backup Circuits with
Regulated Output Voltage
VCC SUPPLY CURRENT
vs. VCC SUPPLY VOLTAGEMAX16023 toc01
VCC SUPPLY VOLTAGE (V)
SUPPLY CURRENT (
MAX16024PTBS25+
VOUT = 2.5V
VTH = 2.93V
VCC SUPPLY CURRENT
vs. TEMPERATUREMAX16023 toc02
TEMPERATURE (°C)
SUPPLY CURRENT (1035-15
MAX16024PTBS25+
VOUT = 2.5V
VTH = 2.93V
BATT SUPPLY CURRENT
vs. VCC SUPPLY VOLTAGEMAX16023 toc03
VCC SUPPLY VOLTAGE (V)
BATT SUPPLY CURRENT (
MAX16024PTBS25+
VOUT = 2.5V
VTH = 2.93V
VBATT = 3.0V
VBATT = 2.8V
BATTERY SUPPLY CURRENT
vs. TEMPERATUREMAX16023 toc04
TEMPERATURE (°C)
BATTERY SUPPLY CURRENT (1035-15
MAX16024PTBS25+
VBATT = +3.0V
VCC = 0
BATT STANDBY CURRENT
vs. TEMPERATUREMAX16023 toc05
TEMPERATURE (°C)
BATT STANDBY CURRENT (nA)1035-15
VCC = 3.3V
VBATT = 3.0V
RESET OUTPUT VOLTAGE LOW
vs. SINK CURRENTMAX16023 toc06
SINK CURRENT (mA)
OUTPUT VOLTAGE LOW (V)8124
MAX16024PTBS25+
Typical Operating Characteristics(VCC = 5V, VBATT= 0, IOUT= 0, TA= +25°C, unless otherwise noted.)
Table 1. Reset Threshold RangesTable 2. Fixed Output Voltage
RESET THRESHOLD RANGES (V)SUFFIXMINTYPMAX4.5084.634.9064.2644.384.6352.9913.083.2392.8452.933.0802.5492.632.7552.2432.322.4252.1172.192.2881.6031.671.7331.5141.5751.639
SUFFIXNOMINAL OUTPUT
VOLTAGE (V)3.33.02.51.81.2
MAX16023/MAX16024
Battery-Backup Circuits with
Regulated Output Voltage
Typical Operating Characteristics (continued)(VCC = 5V, VBATT= 0, IOUT= 0, TA= +25°C, unless otherwise noted.)
VCC FALLING TO RESET DELAY
vs. TEMPERATUREMAX16023 toc07
TEMPERATURE (°C)
DELAY (1035-15
VCC FALLING 10V/ms
RESET TIMEOUT PERIOD
vs. TEMPERATUREMAX16023 toc08
TEMPERATURE (°C)
RESET TIMEOUT PERIOD (ms)35-1510
NORMALIZED RESET THRESHOLD
vs. TEMPERATURE
MAX16023 toc09
TEMPERATURE (°C)
NORMALIZED RESET THRESHOLD1035-15
MAX16024PTBS25+
VOUT = 2.5V
MAXIMUM TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVERESET THRESHOLD OVERDRIVE (mV)
TRANSIENT DURATION (ms)
MAX16023 toc102004006008001000
RESET OCCURS ABOVE THE CURVE
DROPOUT VOLTAGE
vs. LOAD CURRENTMAX16023 toc11
LOAD CURRENT (mA)
DROPOUT VOLTAGE (mV)406020
MAX16024PTBS25+
OUTPUT VOLTAGE
vs. LOAD CURRENTMAX16023 toc12
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)406020
MAX16024PTBS25+
VOUT = 2.5V
TA = -40°C
TA = +25°C
TA = +85°C
OUTPUT VOLTAGE
vs. VCC VOLTAGEMAX16023 toc13
VCC VOLTAGE (V)
OUTPUT VOLTAGE (V)
MAX16024PTBS25+
IOUT = 0
LOAD-TRANSIENT RESPONSEMAX16023 toc14
1ms/div
OUT
AC-COUPLED
100mV/div
50mA
IOUT
20mA/div
10mA
MAX16024PTBS25+
COUT = 10µF
STARTUP RESPONSEMAX16023 toc15
2ms/div
VCC
2V/div
OUT
1V/div
MAX16024PTBS25+
IOUT = 0
MAX16023/MAX16024
Battery-Backup Circuits with
Regulated Output Voltage
MR FALLING TO RESET DELAYMAX16023 toc16
200ns/div
5V/div
RESET
5V/div
CHIP-ENABLE LOCKING OUT
SIGNAL DURING RESETMAX16023 toc17
40µs/div
CEIN
2V/div
CEOUT
2V/div
RESET
5V/div
Typical Operating Characteristics (continued)(VCC = 5V, VBATT= 0, IOUT= 0, TA= +25°C, unless otherwise noted.)
MAX16023/MAX16024
Battery-Backup Circuits with
Regulated Output Voltage
Pin Description
PIN
MAX16023MAX16024NAMEFUNCTIONVCCSupply Voltage Input. Bypass VCC to GND with a 0.1µF capacitor.3BATT
Backup Battery Input. If VCC falls below its reset threshold (VTH), VBATT ≥ VCC, and if
the regulator enters dropout, the regulator is powered from BATT. If VBATT < VCC,
the regulator is powered from VCC. Bypass BATT to GND with a 0.1µF capacitor.MR
Active-Low, Manual-Reset Input. RESET asserts when MR is pulled low. RESET
remains low for the duration of reset timeout period after MR transitions from low to
high. Connect MR to OUT or leave unconnected if not used. MR is internally
connected to VCC through a 30kΩ pullup resistor.—PFI
Power-Fail Comparator Input. Connect PFI to a resistive divider to set the desired PFI
threshold. The PFI input is referenced to an internal VPFT threshold. A VPFI-HYS
internal hysteresis provides noise immunity. The power-fail comparator is powered
from OUT.PFO
Active-Low, Power-Fail Comparator Output. PFO goes low when VPFI falls below the
internal VPFT threshold and goes high when VPFI rises above VPFT + VPFI-HYS
hysteresis.7GNDGroundRESET
Active-Low Reset Output. RESET asserts when VCC falls below the reset threshold or
MR is pulled low. RESET remains low for the duration of the reset timeout period after
VCC rises above the reset threshold and MR goes high. RESET is available in push-
pull and open-drain options.9OUT
Linear Regulator Output Voltage. Available in the following factory-fixed voltages of
1.2V, 1.8V, 2.5V, 3.0V, or 3.3V for all devices. The MAX16024 is also available with
an adjustable output voltage (1.8V to 5.25V). Bypass OUT to GND with a 10µF
capacitor.CEINChip-Enable Input. The input to CE gating circuitry. Connect to GND or OUT if not
used.5SET
Set Output Voltage Input. For the fixed output voltage versions (MAX16024_TB_ _ _),
SET is not used. Connect SET to GND. For MAX16024_TB_, connect SET to an
external resistive divider to set the desired output voltage between 1.8V and 5.25V.6BATT ONActive-High, Battery-On Output. BATT ON goes high when in the battery backup
mode.
—10CEOUT
Active-Low, Chip-Enable Output. CEOUT goes low only when CEIN is low and reset
is not asserted. If CEIN is low when reset is asserted, CEOUT stays low for 12µs (typ)
or until CEIN goes high, whichever occurs first.EPExposed Pad. Internally connected to GND. Connect EP to a large ground plane to
aid heat dissipation. Do not use EP as the only ground connection for the device.
MAX16023/MAX16024
Battery-Backup Circuits with
Regulated Output Voltage
Functional DiagramsMAX16023
PFI
PFO
OUT
GND
VCC
RESETDELAY
LOGIC
LDO
REF
OUT
RESET
BATT
DROPOUT
OUT
