Rainbow Electronics MAX16040 User Manual

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 volt­ages up to 5.5V. The factory-set reset threshold voltage
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 push­pull 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

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

Packages

MAX16033–MAX16040

Low-Power Battery Backup

Circuits in Small µDFN Packages

________________________________________________________________

Maxim Integrated Products

1

19-0882; Rev 0; 7/07

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.

Ordering Information continued on last page.

*

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 Selector
Guide for a listing of device features.

+

Denotes a lead-free package.

T

= Tape and reel.

Pin Configurations and Typical Operating Circuit appear at
end of data sheet.

Ordering Information

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

Selector Guide

Portable/Battery­Powered Equipment

POS Equipment

Critical µP/µC Power
Monitoring

Set-Top Boxes

Controllers

Computers

Fax Machines

Industrial Control

Real-Time Clocks

Intelligent Instrument

PART* TEMP RANGE

MAX16033LLB_ _+T -40°C to +85°C 10 µDFN-10 L1022-1

MAX16033PLB_ _+T -40°C to +85°C 10 µDFN-10 L1022-1

MAX16034LLB_ _+T -40°C to +85°C 10 µDFN-10 L1022-1

MAX16034PLB_ _+T -40°C to +85°C 10 µDFN-10 L1022-1

PIN­PACKAGE

PKG

CODE

PART MR WATCHDOG BATTON RESETIN

MAX16033_ ✓✓✓10 µDFN-10

MAX16034_ ✓✓✓10 µDFN-10

MAX16035_ ✓✓✓10 µDFN-10

MAX16036_ ✓✓ ✓10 µDFN-10

MAX16037_ ✓ ✓ 8 µDFN-8

MAX16038_ ✓✓8 µDFN-8

MAX16039_ ✓✓8 µDFN-8

MAX16040_ ✓✓8 µDFN-8

CEIN/CEOU

PFI, PFO PIN-PACKAGE

MAX16033–MAX16040

Low-Power Battery Backup
Circuits in Small µDFN Packages

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= 2.25V to 5.5V, V

BATT

= 3V, RESET not asserted, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA=

+25°C.) (Note 1)

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.

Terminal Voltages (with respect to GND)
V

CC,

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 (V

OUT

+ 0.3V)

Input Current

V

CC

Peak..............................................................................1A

V

CC

Continuous ............................................................250mA

BATT Peak ....................................................................250mA

BATT Continuous ............................................................40mA

GND ................................................................................75mA

Output Current

OUT ..................................Short-Circuit Protected for up to 5s

RESET, BATTON .............................................................20mA

Continuous Power Dissipation (T

A

= +70°C)

8-Pin µDFN (derate 4.8mW/°C above +70°C) ..........380.6mW

10-Pin µDFN (derate 5mW/°C above +70°C) ...........402.8mW

Operating Temperature Range ...........................-40°C to +85°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

Operating Voltage Range VCC, V

Supply Current in Battery
Backup Mode

BATT Standby Current (Note 3) I

Output Voltage in Battery
Backup Mode

Battery-Switchover Threshold V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

No load (Note 2) 0 5.5 V

BATT

CC

BATT

ON

V

OUT

SW

No load, VCC > V

= 2.8V,

V

BATT

= 0V,

V

CC

excluding I

(V

BATT

< 5.5V

VCC = 4.75V, VCC > VTH, I

VCC = 3.15V, VCC > VTH, I

VCC = 2.5V, VCC > VTH, I

V

BATT

V

BATT

V

BATT

VCC - V

OUT

+ 0.2V) < V

= 4.50V, VCC = 0V, I

= 3.15V, VCC = 0V, I

= 2.5V, VCC = 0V, I

BATT, VCC

VCC = 2.8V 13 30

VCC = 3.6V 16 35Supply Current I

TH

VCC = 5.5V 22 50

TA = +25°C 1

TA = -40°C to +85°C 2

TA = +25°C -0.1 +0.02

CC

T

= -40°C to +85°C -0.3 +0.02

A

= 150mA 3.1

OUT

= 65mA 3.7VCC to OUT On-Resistance R

OUT

= 25mA 4.6

OUT

V

BATT

- 0.2

V

BATT

- 0.15

V

BATT

- 0.15

< V

TH

= 20mA

OUT

= 10mA

OUT

= 5mA

OUT

VCC rising 0

VCC falling -40

µA

µA

µA

Ω

V

mV

MAX16033–MAX16040

Low-Power Battery Backup

Circuits in Small µDFN Packages

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= 2.25V to 5.5V, V

BATT

= 3V, RESET not asserted, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA=

+25°C.) (Note 1)

)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

RESET OUTPUT

MAX160_ _ _L_46 4.50 4.63 4.75

MAX160_ _ _L_44 4.25 4.38 4.50

Reset Threshold V

VCC Falling Reset Delay VCC falling at 10V/ms 25 µs

Reset Active Timeout Period t

RESET Output Low Voltage V

RESET Output High Voltage V

RESET Output Leakage

Current

POWER-FAIL COMPARATOR

PFI Input Threshold V

PFI Hysteresis 1%

PFI Input Current V

PFO Output Low Voltage V

PFO Output High Voltage V

PFO Leakage Current

PFO Delay Time V

MANUAL RESET (MAX16033/MAX16037)

MR Input Voltage

Pullup Resistance to V

Minimum Pulse Width 1µs

Glitch Immunity VCC = 3.3V 100 ns
MR to Reset Delay 120 ns

CC

I

LKG

V

V

TH

RP

OL

OH

PFI

OL

OH

IL

IH

MAX160_ _ _L_31 3.00 3.08 3.15

MAX160_ _ _L_29 2.85 2.93 3.00

MAX160_ _ _L_26 2.55 2.63 2.70

MAX160_ _ _L_23 2.25 2.32 2.38

140 280 ms

I

= 1.6mA, VCC > 2.1V 0.3

RESET asserted

MAX160_ _L only (push-pull), RESET not
asserted, I

MAX160_ _P only (open drain), not asserted 1 µA

V

PFI

PFI

O utp ut asser ted

MAX160_ _L only (push-pull), VCC > V
I

SOURCE

MAX160_ _P only (open drain), V
not asserted

PFI

SOURCE

falling 1.185 1.235 1.285 V

= 0V or V

= 500µA, output not asserted

+ 100mV to V

SINK

= 100µA, VCC > 1.2V 0.4

I

SINK

0.8 x

= 500µA, VCC > V

CC

VCC > 2.1V, I

V

> 1.2V, I

CC

- 100mV 4 µs

PFI

TH(MAX

= 1.6mA 0.3

SINK

= 100µA 0.4

SINK

TH(MAX),

= 5.5V,

PFO

V

CC

-100 +100 nA

0.8 x
V

CC

0.7 x
V

CC

20 165 kΩ

1µA

0.3 x
V

CC

V

V

V

V

V

V

MAX16033–MAX16040

Low-Power Battery Backup
Circuits in Small µDFN Packages

4 _______________________________________________________________________________________

Note 1: All devices are 100% production tested at TA= +25°C. All overtemperature limits are guaranteed by design.
Note 2: V

BATT

can be 0V any time, or VCCcan go down to 0V if V

BATT

is active (except at startup).

Note 3: Positive current flows into BATT.
Note 4: Guaranteed by design.

ELECTRICAL CHARACTERISTICS (continued)

(VCC= 2.25V to 5.5V, V

BATT

= 3V, RESET not asserted, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA=

+25°C.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

WATCHDOG (MAX16034/MAX16038)

Watchdog Timeout Period t

M i ni m um WD I Inp ut P ul se W i d th t

WDI Input Voltage

WDI Input Current -1.0 +1.0 µA

BATTON (MAX16035/MAX16039)

Output Voltage V

Output Short-Circuit Current

RESETIN (MAX16036/MAX16040)

RESETIN Threshold V

RESETIN Input Current 0.01 25 nA

RESETIN to Reset Delay (V

CHIP-ENABLE GATING (MAX16033–MAX16036)

CEIN Leakage Current RESET asserted ±1 µA

CEIN to CEOUT Resistance

CEOUT Short-Circuit Current RESET asserted, V

CEIN to CEOUT Propagation

Delay (Note 4)

CEOUT Output-Voltage High

RESET to CEOUT Delay 1µs

WD

WDI

V

V

OL

RTH

(Note 4) 100 ns

IL

IH

I

= 3.2mA, V

SINK

Sink current, VCC = 5V 60 mA

Source current, V

+ 100mV) to (V

RTH

RESET not asserted, V
V

= VCC / 2, I

CEIN

50Ω source impedance driver,

= 50pF

C

LOAD

VCC = 5V, VCC > V

= 0V, V

V

CC

BATT

= 2.1V 0.4 V

BATT

> 2V 10 30 120 µA

BATT

- 100mV) 1.5 µs

RTH

= V

CC

TH(MAX),

= 10mA

SINK

= 0V 1 2.0 mA

CEOUT

VCC = 4.75V 1.5 7

V

= 3.15V 2 9

CC

SOURCE

SOURCE

= 100µA

= 1µA

BATT

> 2.2V, I

, I

1.00 1.65 2.25 s

0.3 x

V

CC

0.7 x
V

CC

1.185 1.235 1.285 V

100 Ω

0.7 x
V

CC

V

BATT

- 0.1

V

ns

V

MAX16033–MAX16040

Low-Power Battery Backup

Circuits in Small µDFN Packages

_______________________________________________________________________________________

5

Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

SUPPLY CURRENT

vs. TEMPERATURE

20

VCC = 5V

19

18

17

16

15

14

13

SUPPLY CURRENT (µA)

12

11

10

-40 85
TEMPERATURE (°C)

603510-15

VCC-TO-OUT ON-RESISTANCE

vs. TEMPERATURE

1.4

1.2

1.0

0.8

0.6

0.4

-TO-OUT ON-RESISTANCE (Ω)

CC

V

0.2

0

-40 80

VCC = 2.5V

= 25mA

I

OUT

VCC = 3V

= 65mA

I

OUT

TEMPERATURE (°C)

VCC = 4.5V

= 150mA

I

OUT

6550-25 -10 5 20 35

(BACKUP MODE) vs. TEMPERATURE

1.0

0.9

MAX16033 toc01

0.8

0.7

0.6

0.5

0.4

0.3

0.2

BATTERY SUPPLY CURRENT (µA)

0.1

0

-40 85

230

VCC = 5V

225

MAX16033 toc04

220

215

210

205

200

195

RESET TIMEOUT PERIOD (ms)

190

185

180

-40 85

BATTERY SUPPLY CURRENT

V

= 3V

BATT

= 0V

V

CC

TEMPERATURE (°C)

RESET TIMEOUT PERIOD

vs. TEMPERATURE

TEMPERATURE (°C)

BATT-TO-OUT ON-RESISTANCE

1.0

9

MAX16033 toc02

603510-15

MAX16033 toc05

603510-15

8

7

6

5

4

3

2

BATTERY-TO-OUT ON-RESISTANCE (Ω)

1

0

-40 85

120

105

90

75

60

45

30

-TO-RESET PROPAGATION DELAY (µs)

CC

15

V

0

-40 80

vs. TEMPERATURE

VCC = 0V

V

= 2V

BATT

V

= 5V

V

= 3V

BATT

TEMPERATURE (°C)

BATT

603510-15

VCC-TO-RESET PROPAGATION DELAY

vs. TEMPERATURE

VCC FALLING

0.25V/ms

1V/ms

10V/ms

6040-20 0 20

TEMPERATURE (°C)

MAX16033 toc03

MAX16033 toc06

NORMALIZED RESET THRESHOLD

vs. TEMPERATURE

1.003

1.002

1.001

1.000

0.999

0.998

0.997

0.996

0.995

0.994

0.993

NORMALIZED RESET THRESHOLD

0.992

0.991

0.990

-40 80
TEMPERATURE (°C)

MAX16033 toc07

6040200-20

MAXIMUM TRANSIENT DURATION

vs. RESET THRESHOLD OVERDRIVE

300

RESET OCCURS
ABOVE CURVE

250

200

150

100

50

MAXIMUM TRANSIENT DURATION (µs)

0

1 10,000

RESET THRESHOLD OVERDRIVE (VTH - VCC) (mV)

MAX160_ _-46

= 4.63V)

(V

TH

MAX160_ _-29

= 2.93V)

(V

TH

MAX16033 toc08

100010010

MAX16033–MAX16040

Low-Power Battery Backup
Circuits in Small µDFN Packages

6 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(TA = +25°C, unless otherwise noted.)

BATTERY SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX16033 toc09

SUPPLY VOLTAGE (V)

BATTERY SUPPLY CURRENT (µA)

4.54.03.0 3.51.0 1.5 2.0 2.50.5

0

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

-0.25
0 5.0

V

BATT

= 2.8V

VTH = 2.93V

V

BATT

= 2.5V

V

BATT

= 2.3V

RESETIN THRESHOLD

vs. TEMPERATURE

MAX16033 toc10

TEMPERATURE (°C)

RESETIN THRESHOLD (V)

6035-15 10

1.215

1.220

1.225

1.230

1.235

1.240

1.245

1.250

1.210

-40 85

MAX16036/
MAX16040

RESETIN-TO-RESET PROPAGATION

DELAY vs. TEMPERATURE

MAX16033 toc11

TEMPERATURE (°C)

RESETIN-TO-RESET PROPAGATION DELAY (µs)

6035-15 10

1.3

1.5

1.8

2.0

2.3

2.5

2.8

3.0

1.0

-40 85

MAX16036/
MAX16040

VOD = 50mV

CEIN PROPAGATION DELAY

vs. CEOUT LOAD CAPACITANCE

MAX16033 toc12

CEOUT LOAD CAPACITANCE (pF)

CEIN PROPAGATION DELAY (ns)

150125100755025

0.5

1.0

1.5

2.0

2.5

3.0

0

0175

VCC = 3V

VCC = 5V

CEIN TO CEOUT ON-RESISTANCE

vs. TEMPERATURE

MAX16033 toc13

TEMPERATURE (°C)

CEIN TO CEOUT ON-RESISTANCE (Ω)

603510-15

5

10

15

20

25

30

35

0

-40 85

VCC = 3V

VCC = 5V

PFI-TO-PFO DELAY
vs. TEMPERATURE

MAX16033 toc15

TEMPERATURE (°C)

PFI-TO-PFO DELAY (µs)

603510-15

3.25

3.50

4.00

3.75

4.25

4.50

2.25

2.75

2.50

3.00

4.75

5.00

2.00

-40 85

VOD = 30mV

FALLING EDGE

PFI THRESHOLD

vs. TEMPERATURE

MAX16033 toc16

TEMPERATURE (°C)

PFI THRESHOLD (V)

6035-15 10

1.215

1.220

1.225

1.230

1.235

1.240

1.245

1.250

1.210

-40 85

WATCHDOG TIMEOUT PERIOD

vs. TEMPERATURE

MAX16033 toc14

TEMPERATURE (°C)

WATCHDOG TIMEOUT PERIOD (s)

603510-15

1.4

1.5

1.6

1.7

1.8

1.1

1.2

1.3

1.9

2.0

1.0

-40 85

VCC = 5V

MAX16033–MAX16040

Low-Power Battery Backup

Circuits in Small µDFN Packages

_______________________________________________________________________________________ 7

Pin Description

PIN

MAX16033–

MAX16036

(10-pin µDFN)

11RESET

2—CEIN

3 2 PFI Power-Fail Input. PFO goes low when V

4 3 GND Ground

54

MAX16037–

MAX16040

(8-pin µDFN)

NAME FUNCTION

Active-Low Reset Output. RESET remains low when V

MR

WDI

BATTON

RESETIN

threshold (V
pulses when the internal watchdog times out. RESET remains low for the reset
timeout period (t
input goes from low to high, after RESETIN goes high, or after the watchdog triggers
a reset event. The MAX160_ _L is an active-low push-pull output, while the
MAX160_ _P is an active-low open-drain output.

Chip-Enable Input. The input to the chip-enable gating circuit. Connect to GND or
OUT if not used.

Manual-Reset Input (MAX16033/MAX16037). Driving MR low asserts RESET. RESET
remains asserted as long as MR is low and for the reset timeout period (t

MR transitions from low to high. Leave unconnected, or connect to V
MR has an internal 20kΩ pullup to V

Watchdog Input (MAX16034/MAX16038). If WDI remains high or low for longer than
the watchdog timeout period (t
pulse is triggered for the reset timeout period (t
whenever RESET asserts or whenever WDI sees a rising or falling edge (Figure 2).

Battery-On Output (MAX16035/MAX16039). BATTON goes high during battery
backup mode.

Reset Input (MAX16036/MAX16040). When RESETIN falls below 1.235V, RESET
asserts. RESET remains asserted as long as RESETIN is low and for at least t
after RESETIN goes high.

), the manual-reset input is low, or RESETIN is low. It asserts low in

TH

) after VCC rises above the reset threshold, after the manual-reset

RP

is below the reset

CC

falls below 1.235V.

PFI

) after

RP

if not used.

.

CC

), the internal watchdog timer runs out and a reset

WD

). The internal watchdog clears

RP

CC

RP

Active-Low Power-Fail Output. PFO goes low when V

65PFO

76V

8 7 OUT

9 8 BATT

10 — CEOUT

CC

stays low until V
the reset threshold voltage.

Supply Voltage, 1.2V to 5.5V

Output. OUT sources from V
V

CC

Backup Battery Input. When V
BATT if V
switches to V
slowly.

Chip-Enable Output. CEOUT goes low only when CEIN is low and reset is not
asserted. When CEOUT is disconnected from CEIN, CEOUT is actively pulled up to
OUT.

falls below 1.235V. PFO

goes above 1.235V. PFO also goes low when VCC falls below

PFI

when RESET is not asserted and from the greater of

or BATT when VCC is below the reset threshold voltage.

is 40mV greater than VCC. When VCC rises above V

BATT

. The 40mV hysteresis prevents repeated switching if VCC falls

CC

CC

falls below the reset threshold, OUT switches to

CC

PFI

BATT

, OUT