MAX6885 데이터 시트보기 (PDF) - Maxim Integrated

부품명

상세내역

제조사

MAX6885

EEPROM-Programmable, Hex Power-Supply Supervisory Circuits

Maxim Integrated 

EEPROM-Programmable, Hex

Power-Supply Supervisory Circuits

Programmable Outputs

The MAX6884/MAX6885 feature three programmable

active-low outputs: RESET, UV/OV, and WDO. Program

each output for open-drain or weak pullup. An internal

10kΩ resistor connected from each output to a 2.55V

internal LDO provides a weak pullup. During power-up,

the outputs are held low for 1V < VCC < VUVLO. Any

output programmed to depend on no condition always

remains in its active state. For example, if the state of

UV/OV is not programmed to depend on any condition,

UV/OV will always be low. Figure 3 shows a timing dia-

gram of a typical relationship between a monitored

input voltage and outputs RESET and UV/OV. RESET

and UV/OV are a function of only IN1.

RESET

Program RESET to depend on MR, UV/OV, WDO, or

any programmable primary voltage-detector input (see

Table 6). As an example, RESET may depend on the

IN3 primary undervoltage threshold, MR, UV/OV, and

WDO. Write 1’s to R11h[1:0], R11h[4], and R12h[7] to

configure as indicated. IN3 must be above the under-

voltage threshold, MR must be high, UV/OV must be

deasserted, and WDO must be deasserted to be a

logic “1,” then RESET deasserts. The logic state of

RESET, in this example, is equivalent to the logical

statement:

IN3 · MR · UV/OV · WDO

RESET remains low for its programmed timeout period

(tRP) after all assertion-causing conditions are

removed. Program timeout periods for RESET from

25µs to 1600ms (see Table 6). Configure RESET for

open-drain or weak pullup through bit R12h[0].

SECONDARY

THRESHOLD

(OVERVOLTAGE)

VIN1

PRIMARY

THRESHOLD

UV/OV

RESET

Figure 3. Output Timing Diagram

tUP

tRP

______________________________________________________________________________________ 17

Share Link: