A8739EEETR-T Allegro Microsystems Inc, A8739EEETR-T Datasheet - Page 9

• Manufacturer Part Number: A8739EEETR-T
• Description: Photoflash Capacitor Charger
• Manufacturer: Allegro Microsystems Inc
• Type: Flash/Torchr

Specifications of A8739EEETR-T

• Number Of Outputs: *
• Internal Driver: No
• Type - Primary: Flash/Torch
• Voltage - Supply: *
• Mounting Type: Surface Mount
• Package / Case: 8-UFDFN Exposed Pad
• Operating Temperature: *
• Voltage - Output: *
• Frequency: *
• Current - Output / Channel: *
• Internal Switch(s): Yes
• Efficiency: 75%
• Topology: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 620-1365-2

A8739
Note: Output voltage is sensed from the primary side winding when the switch turns off. This duration, t
to be long enough (>200 ns) in order to obtain an accurate measurement. The value of t
primary inductance, L
R
R
BAT
BAT
Final Output Voltage versus Secondary Side Conduction Time
Final Output Voltage versus Battery Voltage at Various ILIM
= 0 Ω, Transformer L
= 0 Ω, Transformer L
328
327
326
325
324
323
322
321
320
328
327
326
325
324
323
322
321
320
1.5
150
Ultra-Small Mobile Adjustable Xenon Photoflash
Primary
200
2.0
, and the turns ratio, N, as given by: t
250
PRIMARY
at Various Battery Voltages
PRIMARY
2.5
300
3.0
= 12.8 μH, N =10.25, V
= 12.8 μH, N =10.25, V
Battery Voltage (V)
350
t
off
(ns)
3.5
400
Capacitor Charger with IGBT Driver
450
4.0
500
4.5
IN
IN
=3.6 V, at room temperature
=3.6 V, at room temperature
off
550
= (I
5.0
SWlim
600
× L
5.5
650
PRIMARY
off
× N) / V
depends on I
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
ILIM15 (0.51A)
ILIM13 (0.65A)
ILIM11 (0.79A)
ILIM9 (0.93A)
ILIM7 (1.07A)
ILIM5 (1.22A)
ILIM3 (1.36A)
ILIM1 (1.50A)
V
BAT
5.0
4.2
3.6
2.2
OUT
(V)
.
off
SWlim
, has
,
9