MAX1577Y Datasheet, PDF (5/11 Pages) Maxim Integrated Products – 1.2A White LED Regulating Charge Pump for Camera Flashes and Movie Lights

1.2A White LED Regulating Charge Pump for
Camera Flashes and Movie Lights
Pin Description
PIN
NAME
1
EN1
Control Logic Input (see Table 1)
FUNCTION
2
CP
Transfer Capacitor Positive Connection. Connect a 1µF capacitor (or 2.2µF for I_OUT > 600mA) from
CP to CN.
3
CN
Transfer Capacitor Negative Connection. Connect a 1µF capacitor (or 2.2µF for I_OUT > 600mA) from
CP to CN.
4
EN2
Control Logic Input (see Table 1)
5
GND
Ground
6
IN
Input Supply Voltage. Connect IN to a battery or supply voltage from 2.7V to 5.5V. Connect a 4.7µF
ceramic capacitor from IN to GND.
7
CS
Current-Sense Input. Connect a current-sense resistor from OUT to CS to set the output current.
Connect the anodes of the LEDs to CS and the cathodes to GND.
8
OUT
Output. Connect a 10µF ceramic capacitor from OUT to GND. In shutdown, OUT is pulled to GND
with an internal 5kΩ resistor.
—
EP
Exposed Pad. Connect the exposed pad to GND directly under the IC.
Table 1. Enable, Dimming, Voltage Mode, and Overvoltage Protection
EN1
EN2 DIMMING LEVEL ^{CS THRESHOLD}
VOLTAGE MODE
OVP
(V_OUT - V_CS)
MAX1577Z MAX1577Y MAX1577Z MAX1577Y
0
0
Shutdown
—
—
—
—
—
0
1
20% Current
60mV
5.10V
3.40V
5.30V
5.15V
1
0
33% Current
100mV
5.10V
4.60V
5.30V
5.17V
1
1
100% Current
300mV
5.10V
5.10V
5.30V
5.30V
Note: A “0” indicates EN_ is logic low or connected to GND. A “1” indicates EN_ is logic high or connected to IN.
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