A8740EEETR-T Allegro Microsystems Inc, A8740EEETR-T Datasheet - Page 3

• 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
DONE
GATE
TRIG
GND
Pin-out Diagram
1
2
3
4
(Top View)
CHARGE
VIN_DRV
VBAT
PAD
TRIG
8
7
6
5
V
Reference
SW
CHARGE
VIN_DRV
VBAT
SW
ILIM
– V
V
BAT
DS
ref
Terminal List
Number
1
2
3
4
5
6
7
8
–
t
on
Detector
18 μs
OCP
(max)
DCM
Ultra Small Mobile Phone Xenon Photoflash
VIN_DRV
CHARGE
Functional Block Diagram
¯ D ¯ ¯ O ¯ ¯ N ¯ ¯ E ¯
Name
GATE
VBAT
TRIG
GND
PAD
SW
Open collector output, pulls low when output reaches target value and CHARGE is
high. Goes high during charging or whenever CHARGE is low.
IGBT trigger input.
IGBT gate drive output.
Ground connection.
Drain connection of internal DMOS switch. Connect to transformer primary winding.
Battery voltage.
Input voltage. Connect to 3 to 5.5 V bias supply. Decouple V
ceramic capacitor placed close to this pin.
Charge enable pin. Set this pin low to shut down the chip.
Exposed pad for enhanced thermal dissipation. Connect to ground plane.
S
R
Capacitor Charger with IGBT Driver
H
Triggered Timer
t
off
18 μs
Q
Q
(max)
L
Control Logic
Enable
S
R
Q
Q
V IN_DRV
GND
IGBT Driver
Function
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
DMOS
IN
voltage with 0.1 μF
SW
GATE
DONE
3