ZXCT1010_06 ZETEX [Zetex Semiconductors], ZXCT1010_06 Datasheet - Page 6

• Manufacturer Part Number: ZXCT1010_06
• Description: Enhanced high-side current monitor
• Manufacturer: ZETEX [Zetex Semiconductors]

Typical circuit application
Where R
motors, a charging battery or further circuitry
that requires monitoring, R
selected on specific requirements of accuracy,
size and power rating.
Li-Ion charger circuit
The figure below shows the ZXCT1010 supporting the Benchmarq bq2954 charge management
IC. Most of the support components for the bq2954 are omitted for clarity. This design also uses
the Zetex FZT789A high current Super- PNP as the switching transistor in the DC-DC step down
converter and the FMMT451 as the drive NPN for the FZT789A. The circuit can be configured to
charge up to four Li-Ion cells at a charge current of 1.25A. Charge can be terminated on maximum
voltage, selectable minimum current, or maximum time out. Switching frequency of the PWM
loop is approximately 120kHz.
Issue 9 - July 2006
© Zetex Semiconductors plc 2006
Charger Input
support components omitted for clarity
bq2954
5V
LOAD
BC81725
represents any load including DC
MOD pin
SNS pin
BAS16
FMMT451
FZT789A
1kΩ
220Ω
10µH
SENSE
ZHCS1000
140µH
can be
100Ω
100Ω
V in
I out
0.2Ω
ZXCT1010
+
6
-
Load
To Battery +
ZXCT1010
www.zetex.com