High power digital camera photoflash charger

Specification

275V

Efficiency =

69%

Charging time =

5 seconds

ZXSC440

SEMICO NDUC TORS

ISSUE 1 - JANUARY 2005

11

Circuit diagram

Ref

Value

Package

Part number

Manufacturer

Notes

U1

MSOP8

ZXSC440

Zetex

U2

SOT23-6

ZXTD6717

Zetex

NPN/PNP dual

Q1

SOT23

FMMT619

Zetex

50V NPN low sat

D1

200V

SOT23

BAS21

Philips

200V fast rectifier

D2

200V

SOT23

BAS21

Philips

200V fast rectifier

D3

2A

SOT23-6

ZLLS2000

Zetex

2A Schottky diode

Tx1

PAO367

Pulse

See note

(1)

R1

22m

0805

RL1210

Cyntec

R2

130

0805

Generic

Generic

R3

2k2

0805

Generic

Generic

R4

10M /400V

Axial

Generic

Generic

Output voltage across resistor

R5

10k

0805

Generic

Generic

C1

100uF/10V

0805

Generic

Murata

C2

220nF

0805

GRM Series

Murata

C3

10pF/500V

1206

Generic

Generic

Output voltage seen across capacitor

C4

10nF/6V3

1206

Generic

Generic

C5

120uF/330V

Radial

FW Series

Rubycon

Photoflash capacitor

Bill of materials

NOTES:

(1) Transformer specification: Primary inductance: 24uH, Core: Pulse PAO367, Turns ratio: 1:12