Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - system monitor Reserve capacity circuit DFN 10

General Description

The MAX16033–MAX16040 supervisory circuits reduce

the complexity and number of components required for

power-supply monitoring and battery-control functions in

microprocessor (μP) systems. The devices significantly

improve system reliability and accuracy compared to other

ICs or discrete components. The MAX16033–MAX16040

provide μP reset, backup-battery switchover, power-fail

warning, watchdog, and chip-enable gating features.

The MAX16033–MAX16040 operate from supply volt-

ages up to 5.5V. The factory-set reset threshold volt-

age ranges from 2.32V to 4.63V. The devices feature a

manual-reset input (MAX16033/MAX16037), a watchdog

timer input (MAX16034/MAX16038), a battery-on output

(MAX16035/MAX16039), an auxiliary adjustable-reset

input (MAX16036/MAX16040), and chip-enable gating

(MAX16033–MAX16036). Each device includes a power-

fail comparator and offers an active-low push-pull reset or

an active-low open-drain reset.

The MAX16033–MAX16040 are available in 2mm x 2mm,

8-pin or 10-pin μDFN packages and are fully specified

from -40°C to +85°C.

Applications

● Portable/Battery-

Powered Equipment

● POS Equipment

● Critical μP/μC Power

Monitoring

● Set-Top Boxes

● Controllers

● Computers

● Fax Machines

● Industrial Control

● Real-Time Clocks

● Intelligent Instrument

Features

● Low 1.2V Operating Supply Voltage

● Precision Monitoring of 5.0V, 3.3V, 3.0V, and 2.5V

Power-Supply Voltages

● Independent Power-Fail Comparator

● Debounced Manual-Reset Input

● Watchdog Timer, 1.6s Timeout

● Battery-On Output Indicator

● Auxiliary User-Adjustable RESETIN

● Low 13μA Quiescent Supply Current

● Two Available Output Structures:

Active-Low Push-Pull Reset

Active-Low Open-Drain Reset

● Active-Low Reset Valid Down to 1.2V

● Power-Supply Transient Immunity

● 140ms (min) Reset Timeout Period

● Small 2mm x 2mm, 8-Pin and 10-Pin μDFN Paclages

Ordering Information continued on last page.

Pin Configurations and Typical Operating Circuit appear at

end of data sheet

19-0882; Rev 1; 5/14

*These parts offer a choice of reset threshold voltages. From

the Reset Threshold Ranges table, insert the desired threshold

voltage code in the blank to complete the part number. See the

Selector Guide for a listing of device features.

+Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.

Note: Replace “_” with L for push-pull or P for open-drain RESET and PFO outputs.

PART* TEMP RANGE PIN-PACKAGE

MAX16033LLB_ _+T -40°C to +85°C 10 µDFN

MAX16033PLB_ _+T -40°C to +85°C 10 µDFN

MAX16034LLB_ _+T -40°C to +85°C 10 µDFN

MAX16034PLB_ _+T -40°C to +85°C 10 µDFN

PART MR WATCHDOG BATTON RESETIN CEIN/CEOUT PFI, PFO PIN-PACKAGE

MAX16033_

ü ü ü

10 µDFN-10

MAX16034_

ü ü ü

10 µDFN-10

MAX16035_

ü ü ü

10 µDFN-10

MAX16036_

ü ü ü

10 µDFN-10

MAX16037_

ü ü

8 µDFN-8

MAX16038_

ü ü

8 µDFN-8

MAX16039_

ü ü

8 µDFN-8

MAX16040_

ü ü

8 µDFN-8

MAX16033–MAX16040 Low-Power Battery-Backup

Circuits in Small μDFN Packages

Ordering Information

Selector Guide

Summary of content (20 pages)

PAGE 1
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages General Description The MAX16033–MAX16040 supervisory circuits reduce the complexity and number of components required for power-supply monitoring and battery-control functions in microprocessor (μP) systems. The devices significantly improve system reliability and accuracy compared to other ICs or discrete components.
PAGE 2
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Absolute Maximum Ratings Terminal Voltages (with respect to GND) VCC, BATT, OUT.......................................................-0.3V to +6V RESET (open drain), PFO (open drain) ....................-0.3V to +6V RESET (push-pull), PFO (push-pull), BATTON, RESETIN, WDI MR, CEIN, CEOUT, PFI...........................-0.3V to (VOUT + 0.3V) Input Current VCC Peak.....................................................................
PAGE 3
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Electrical Characteristics (continued) (VCC = 2.25V to 5.5V, VBATT = 3V, RESET not asserted, TA = -40°C to +85°C, for MAX16039PLA31+T, TA = -55°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX MAX160_ _ _L_46 4.50 4.63 4.75 MAX160_ _ _L_44 4.25 4.38 4.50 MAX160_ _ _L_31 3.00 3.08 3.15 MAX160_ _ _L_29 2.85 2.93 3.00 MAX160_ _ _L_26 2.55 2.
PAGE 4
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Electrical Characteristics (continued) (VCC = 2.25V to 5.5V, VBATT = 3V, RESET not asserted, TA = -40°C to +85°C, for MAX16039PLA31+T, TA = -55°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX 1.00 1.65 2.25 UNITS WATCHDOG (MAX16034/MAX16038) Watchdog Timeout Period tWD Minimum WDI Input Pulse Width tWDI WDI Input Voltage (Note 4) 100 VIL 0.
PAGE 5
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) 17 16 15 14 13 12 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 -15 10 35 60 85 10 35 60 1.0 VCC = 0V 9 8 VBATT = 2V 7 6 5 4 3 2 1 0 85 VBATT = 5V VBATT = 3V -40 -15 10 35 60 85 RESET TIMEOUT PERIOD vs. TEMPERATURE VCC-TO-RESET PROPAGATION DELAY vs. TEMPERATURE VCC = 2.5V IOUT = 25mA 1.0 0.8 VCC = 4.5V IOUT = 150mA VCC = 3V IOUT = 65mA 0.
PAGE 6
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) 1.235 VBATT = 2.5V 1.00 1.230 VBATT = 2.3V 0.75 1.225 0.50 1.220 0.25 1.215 0 -0.25 0 1.210 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 SUPPLY VOLTAGE (V) -40 CEIN PROPAGATION DELAY vs. CEOUT LOAD CAPACITANCE 2.0 VCC = 3V 1.5 VCC = 5V 1.0 0.5 0 0 25 50 75 100 125 150 35 60 175 2.5 2.3 2.0 1.8 1.5 1.3 1.
PAGE 7
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Pin Description PIN MAX16033– MAX16036 (10-pin µDFN) MAX16037– MAX16040 (8-pin µDFN) NAME 1 1 RESET 2 — CEIN 3 2 PFI 4 3 GND 5 4 FUNCTION Active-Low Reset Output. RESET remains low when VCC is below the reset threshold (VTH), the manual-reset input is low, or RESETIN is low. It asserts low in pulses when the internal watchdog times out.
PAGE 8
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Pin Description (continued) BATTON (MAX16035/MAX16039 ONLY) 1.235V MAX16033 MAX16040 VCC OUT CHIP-ENABLE OUTPUT CONTROL BATT CEIN (MAX16033–MAX16036 ONLY) CEOUT RESET GENERATOR MR (MAX16033/MAX16037 ONLY) WATCHDOG TRANSITION DETECTOR WDI (MAX16034/MAX16038 ONLY) RESET WATCHDOG TIMER RESETIN (MAX16036/MAX16040 ONLY) PFO 1.235V 1.235V GND www.maximintegrated.
PAGE 9
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Detailed Description The Typical Operating Circuit shows a typical connection for the MAX16033–MAX16040. OUT powers the static random-access memory (SRAM). If VCC is greater than the reset threshold (VTH), or if VCC is lower than VTH but higher than VBATT, VCC is connected to OUT. If VCC is lower than VTH and VCC is less than VBATT, BATT is connected to OUT. OUT supplies up to 200mA from VCC.
PAGE 10
MAX16033–MAX16040 Backup-Battery Switchover To preserve the contents of the RAM in a brownout or power failure, the MAX16033–MAX16040 automatically switch to back up the battery installed at BATT when the following two conditions are met: 1) VCC falls below the reset threshold voltage. 2) VCC is below VBATT. Table 1 lists the status of the inputs and outputs in batterybackup mode. The devices do not power up if the only voltage source is VBATT. OUT only powers up from VCC at startup. Table 1.
PAGE 11
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages BATTON Indicator (MAX16035/MAX16039 Only) Power-Fail Comparator The MAX16033–MAX16040 issue an interrupt (nonmaskable or regular) to the μP when a power failure occurs. The power line is monitored by two external resistors connected to the power-fail input (PFI). When the voltage at PFI falls below 1.235V, the power-fail output (PFO) drives the processor’s NMI input low.
PAGE 12
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages RESET A μP’s reset input puts the μP in a known state. The MAX16033–MAX16040 μP supervisory circuits assert a reset to prevent code-execution errors during power-up, power-down, and brownout conditions. RESET asserts when VCC is below the reset threshold voltage and for at least 140ms (tRP) after VCC rises above the reset threshold. RESET also asserts when MR is low (MAX16033/MAX16037) or when RESETIN is below 1.
PAGE 13
MAX16033–MAX16040 START Low-Power Battery-Backup Circuits in Small μDFN Packages VCC VCC SET WDI LOW SUBROUTINE OR PROGRAM LOOP SET WDI HIGH RESET MAX16033 MAX16040 V+ MR R1 PFI RETURN TO µP R2 PFO GND END Figure 6. Watchdog Flow Diagram Figure 7. Monitoring an Additional Power Supply Watchdog Software Considerations Connect PFO to MR in applications that require RESET to assert when the second voltage falls below its threshold.
PAGE 14
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages (a) (b) VCC VIN VCC VIN MAX16033 MAX16040 R1 MAX16033 MAX16040 R1 PFI R2 PFI R3 C1 R2 C1 R3 PFO (PUSH-PULL) PFO (PUSH-PULL) GND GND TO µP TO µP PFO PFO 0V VL VTRIP VH R1   = VTRIP VPFT1 +   R2  R1 R1   = (VPFT + VPFH)1 + + VH   R2 R3  R1 R1  R1  V= + VCC L VPFT1 + −  R2 R3  R3 VPFT = 1.
PAGE 15
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Monitoring a Negative Voltage 3.0V OR 3.3V Connect the circuit, as shown in Figure 9, to use the power-fail comparator to monitor a negative supply rail. PFO stays low when V- is good. When V- rises to cause PFI to be above +1.235V, PFO goes high. Ensure VCC comes up before the negative supply. VCC Negative-Going VCC Transients The MAX16033–MAX16040 are relatively immune to short-duration, negative-going VCC transients.
PAGE 16
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Device Marking Codes PART TOP MARK PART TOP MARK PART TOP MARK PART TOP MARK MAX16033LLB23+T +ABE MAX16035LLB23+T +ACC MAX16037LLA23+T +ABX MAX16039LLA23+T +ACV MAX16033LLB26+T +ABF MAX16035LLB26+T +ACD MAX16037LLA26+T +ABY MAX16039LLA26+T +ACW MAX16033LLB29+T +ABG MAX16035LLB29+T +ACE MAX16037LLA29+T +ABZ MAX16039LLA29+T +ACX MAX16033LLB31+T +ABH MAX16035LLB31+T +ACF MAX16037LLA31+T +ACA MAX16
PAGE 17
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Pin Configurations CEOUT BATT OUT VCC PFO CEOUT BATT OUT VCC PFO TOP VIEW 10 9 8 7 6 10 9 8 7 6 MAX16035 MAX16036 MAX16033 MAX16034 10-µDFN ( ) FOR MAX16034 ONLY 10-µDFN ( ) FOR MAX16036 ONLY PFO CEIN GND GND PFI PFI 5 VCC CEIN 4 OUT RESET 3 RESET 2 BATT 1 MR (WDI) 5 PFO 4 VCC 3 OUT 2 BATT 1 BATTON (RESETIN) + + 8 7 6 5 8 7 6 5 MAX16037 MAX16038 MAX16039 MAX16040 MR
PAGE 18
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Typical Operating Circuit 2.4V TO 5.5V 0.1µF VCC BATT ADDITIONAL DC VOLTAGE CMOS RAM CE OUT 0.1µF MAX16033 MAX16040 R3 REALTIME CLOCK RESETIN* R4 ADDITIONAL DC VOLTAGE A0–A15 RESET R1 PFI R2 RESET PFO I/O WDI*** I/O µP CEOUT** CEIN** GND ADDRESS DECODE * RESETIN APPLIES TO MAX16035/MAX16039 ONLY. **CEIN AND CEOUT APPLY TO MAX16033–MAX16036 ONLY. ***WDI APPLIES TO MAX16034/MAX16038 ONLY. www.maximintegrated.
PAGE 19
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Ordering Information (continued) PART* Reset Threshold Ranges TEMP RANGE PIN-PACKAGE MAX16035LLB_ _+T -40°C to +85°C 10 µDFN MIN TYP MAX MAX16035PLB_ _+T -40°C to +85°C 10 µDFN 46 4.50 4.63 4.75 MAX16036LLB_ _+T -40°C to +85°C 10 µDFN MAX16036PLB_ _+T -40°C to +85°C 10 µDFN 44 4.25 4.38 4.50 MAX16037LLA_ _+T -40°C to +85°C 8 µDFN 31 3.00 3.08 3.15 MAX16037PLA_ _+T -40°C to +85°C 8 µDFN 29 2.
PAGE 20
MAX16033–MAX16040 Low-Power Battery-Backup Circuits in Small μDFN Packages Revision History REVISION NUMBER REVISION DATE 1 5/14 PAGES CHANGED DESCRIPTION Data sheet rebranded; updated Electrical Characteristics and Ordering Information tables to support MAX16039PLA31+T option at -55°C 2, 19 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.