Rainbow Electronics DS2715 - Manual (Page 5)

DS2715: NiMH Cell Pack Charge Controller
5 of 12
Figure 1. BLOCK DIAGRAM
State Machine
Charge
Timer
Regulator
LED1
VDD
LED2
UVLO
Oscillator
+
-
Pre-Charge
Low Cells
Fast Charge
Exit on Full
Or Timeout
25% Top-Off Charge
(Set by Timer)
SNS+
R
E
F
Vbatt
THM
Rt
Cbias
Mode
Vch
DS2715
Rt start-up test
+
-
Disch. Detect Ref
HV
HV
HV
Done, Waiting for event
to start charging
Pwr
Pwr
Vsns
Ref
121mV,
33mV,
10mV
AMP
or
Comp
@-0.01V
Rt
A
D
C
RS Latch
Latch is set until
Vsns negative WRT Vss
+
-
R
Th
Disable during
discharge
Div
SNS-
VSS
VSS
V
UVLO
Ref
M
U
X
SNS+
Ref