Rainbow Electronics MAX16021 - Manual (Page 11)

MAX16016/MAX16020/MAX16021
Low-Power µP Supervisory Circuits with
Battery-Backup Circuit and Chip-Enable Gating
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Pin Description—MAX16020/MAX16021 (continued)
PIN
MAX16020 MAX16021
NAME FUNCTION
9 9 WDO
Active-Low Watchdog Output. WDO asserts when WDI remains high or low longer than the
watchdog timeout period. WDO returns high on the next WDI transition or when a reset is
asserted.
10 10 PFO
Active-Low Power-Fail Comparator Output. PFO goes low when V PFI falls below the internal
0.6V V PFT threshold and goes high when V PFI rises above V PFT + V PFI-HYS hysteresis.
11 11 GND Ground
12 12 RESET
Active-Low Reset Output. RESET asserts when V CC falls below the reset threshold or MR is
pulled low. RESET remains low for the duration of the reset timeout period after V CC rises
above the reset threshold and MR goes high.
13 13 OUT
Switched Output. OUT is connected to V CC when the reset output is not asserted or when
V CC is greater than V BATT . OUT connects to BATT when RESET is asserted and V BATT is
greater than V CC . Bypass OUT to GND with a 0.1µF (min) capacitor.
14 14 CEOUT
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.
15 15 CEIN Chip-Enable Input. The input to CE gating circuitry. Connect to GND or OUT if not used.
16 16 V CC Supply Voltage Input. Bypass V CC to GND with a 0.1µF capacitor.
— — EP
Exposed 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.