MAX4914BELT-T 데이터 시트보기 (PDF) - Maxim Integrated

부품명

상세내역

일치하는 목록

MAX4914BELT-T

100mA/200mA/300mA Current-Limit Switches with Low Shutdown Reverse Current

Maxim Integrated 

100mA/200mA/300mA Current-Limit Switches

with Low Shutdown Reverse Current

REVERSE CURRENT

DETECTOR

BLANKING TIME

CIRCUITRY

FLAG

N

FORWARD CURRENT

DETECTOR

N

IN

OUT

ON

UNDERVOLTAGE

LOCKOUT

+2.0V

LOGIC

AUTO-

RETRY

MAX4914B

GND

MAX4915A/B

MAX4917A/B

Figure 1. Functional Diagram

Detailed Description

The MAX4914B/MAX4915A/B/MAX4917A/B are for-

ward/reverse current-limited switches that operate from

a +2.3V to +5.5V input voltage range and guarantee a

100mA, 200mA, and 300mA minimum current-limit

threshold for different options. The voltage drop across

an internal sense resistor is compared to two reference

voltages to indicate a forward or reverse current-limit

fault. When the load current exceeds the preset current

limit for greater than the fault-blanking time, the switch

opens and FLAG asserts.

The MAX4915A/MAX4917A have an autoretry function

that turns on the switch again after an internal retry time

expires. If the faulty load condition is still present after

the blanking time, the switch turns off again and the

cycle is repeated. If the faulty load condition is not pre-

sent, the switch remains on. During this retry time,

FLAG remains low until the fault is removed.

The MAX4914B/MAX4915B/MAX4917B do not have the

autoretry option, and the switch remains in latchoff

mode until the ON pin or the input power is cycled from

high to low and then high again.

The undervoltage-lockout (UVLO) circuit prevents erro-

neous switch operation when the input voltage goes

too low.

Reverse Current Protection

All devices limit the reverse current (VOUT to VIN) from

exceeding the maximum IREV value. The switch is shut off

and FLAG is asserted if the reverse current-limit condition

persists for more than the blanking time. This feature pre-

vents excessive reverse currents from flowing through the

device to the source. When the device is in shutdown

(VON < VIL), the current from OUT to IN does not exceed

1µA (max).

Switch-On/Off Control

Toggle ON high to enable the current-limited switches.

The switches are continuously on only if VIN exceeds the

UVLO threshold (typically 2V) and there is no fault. When

a forward/reverse current fault is present or the die

exceeds the thermal-shutdown temperature of +150°C,

OUT is internally disconnected from IN and the supply

current decreases to 8µA (latchoff). The switch is now

operating in one of its off states. The switch-off state also

occurs when driving ON low, thus reducing the supply

current (shutdown) to 0.01µA (typ). Table 1 illustrates the

ON/OFF state.

FLAG Indicator

All devices feature a latched fault output, FLAG.

Whenever a fault is activated, it latches the FLAG out-

put low and also turns the switch off. FLAG is an open-

6 _______________________________________________________________________________________

Share Link: