a8438eej-t Allegro MicroSystems, Inc., a8438eej-t Datasheet - Page 3

• Manufacturer Part Number: a8438eej-t
• Description: A8438 Photoflash Capacitor Charger With Igbt Driver
• Manufacturer: Allegro MicroSystems, Inc.

A8438
IGBTDRV
CHARGE
Device Pin-out Diagram
GND
VIN
NC
1
2
3
4
5
CHARGE
TRIGGER
DONE
ILIM
VIN
I
LIM
10
9
8
7
6
Decoder
ILIM
FB
DONE
TRIGGER
SW
IGBTDRV
V IN
Adjustable
Reference
Terminal List Table
Number
1.2 V
10
1
2
3
4
5
6
7
8
9
CMP3
Functional Block Diagram
CMP2
Photoflash Capacitor Charger with IGBT Driver
Comparator
Comparator
DCM
I
LIM
GND
TRIGGER
IGBTDRV
CHARGE
Name
GND
ILIM
¯ D ¯ ¯ O ¯ ¯ N ¯ ¯ E ¯
VIN
SW
Enable
NC
FB
H → L
Triggered Timer
18 μs
No connection
IGBT driver gate drive output
Power supply input
Device ground
Charging enable; set to low to power-off the A8438
Switch, internally connected to the DMOS power FET drain
Strobe signal input
Open drain, when pulled low by internal MOSFET, indicates that
charging target level has been reached
Output voltage feedback
Switch current limit setting; sets three discreet levels
Control Logic
S
R
SET
One-Shot
CLR
Q
Q
Q
Q
SET
CLR
S
R
Q
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
Function
CMP1
40 V
DMOS
1.2 V
FB
SW
3