A8740EEETR-T Allegro Microsystems Inc, A8740EEETR-T Datasheet - Page 8

• Manufacturer Part Number: A8740EEETR-T
• Description: Photoflash Capacitor Charger
• Manufacturer: Allegro Microsystems Inc
• Series: -r

Specifications of A8740EEETR-T

• Constant Current: -
• Constant Voltage: -
• Topology: Flyback
• Number Of Outputs: 1
• Internal Driver: No
• Type - Primary: Flash/Torch
• Type - Secondary: -
• Frequency: -
• Voltage - Supply: 1.5 V ~ 5.5 V
• Voltage - Output: -
• Mounting Type: *
• Package / Case: *
• Operating Temperature: -40°C ~ 85°C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

A8740
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.
Transformer L
Transformer L
328
327
326
325
324
323
322
321
320
319
318
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
1.5
1.5
Average Input Current versus Battery Voltage
Final Output Voltage versus Battery Voltage
Ultra Small Mobile Phone Xenon Photoflash
PRIMARY
2.0
PRIMARY
2.0
2.5
2.5
= 12.8 μH, N =10.25, V
= 12.8 μH, N =10.25, V
3.0
Battery Voltage (V)
3.0
Battery Voltage (V)
Capacitor Charger with IGBT Driver
3.5
3.5
4.0
4.0
IN
IN
=3.6 V, at room temperature
=3.6 V, at room temperature
4.5
4.5
5.0
5.0
5.5
5.5
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
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