Low-Power Battery Backup

Circuits in Small µDFN Packages

_______________________________________________________________________________________

7

Pin Description

PIN

MAX16033–

MAX16036

(10-pin µDFN)

MAX16037–

MAX16040

(8-pin µDFN)

NAME

FUNCTION

11

RESET

pulses when the internal watchdog times out. RESET remains low for the reset

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.

2—

CEIN

Chip-Enable Input. The input to the chip-enable gating circuit. Connect to GND or

OUT if not used.

3

2

PFI

4

3

GND

Ground

MR

Manual-Reset Input (MAX16033/MAX16037). Driving MR low asserts RESET. RESET

MR has an internal 20k

WDI

Watchdog Input (MAX16034/MAX16038). If WDI remains high or low for longer than

whenever RESET asserts or whenever WDI sees a rising or falling edge (Figure 2).

BATTON

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

backup mode.

54

RESETIN

Reset Input (MAX16036/MAX16040). When RESETIN falls below 1.235V, RESET

after RESETIN goes high.

65

PFO

the reset threshold voltage.

76

Supply Voltage, 1.2V to 5.5V

8

7

OUT

9

8

BATT

slowly.

10

—

CEOUT

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.