A8732
Ultra Small Mobile Phone Xenon Photoflash
Capacitor Charger with IGBT Driver
Average Input Current versus Battery Voltage at Various ILIM
Transformer LPRIMARY = 12.8 μH, N =10.25, VIN =3.6 V, at room temperature
0.7
0.6
ILIM1 (1.50A)
0.5
ILIM3 (1.36A)
ILIM5 (1.22A)
0.4
ILIM7 (1.07A)
0.3
ILIM9 (0.93A)
ILIM11 (0.79A)
0.2
ILIM13 (0.65A)
0.1
ILIM15 (0.51A)
0.0
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
Battery Voltage (V)
Note: Peak switch current is limited by the maximum on-time and di/dt of the transformer primary
current; therefore, average input current drops at very low battery voltage.
Allegro MicroSystems, Inc.
10
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com