Datasheet

DS2711/DS2712: Loose-Cell NiMH Chargers
4 of 15
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Charge Timer Accuracy
R
TMR
= 100kΩ
-5 +5 %
Charge Timer Range t
CTMR-RANGE
0.5 10 Hours
ELECTRICAL CHARACTERISTICS: TIMING (continued)
(4.0V ≤ V
DD
≤ 5.5V, T
A
= -20°C to +70°C, unless otherwise noted.)
Note 1: Voltages relative to V
SS
.
Note 2: I
MTST
current is applied as a source current and as a sink current within 5ms after power-up.
Note 3: When operating in two-cell-series charge configuration, the DMSEL pin must have less than 50pF of external load capacitance for
proper operation. If the load capacitance is greater than 50pF, a resistor voltage-divider should be used to maintain DMSEL at V
DD
/2.
Note 4: Specification applicable during charge cycle with T
A
= 0°C to +70°C.
Note 5: V
BAT-MAX1
and V
BAT-MAX1
are generated from the same reference. Their ranges never overlap.
Note 6: V
THM-MIN,
V
THM-MAX,
and V
THM-STOP
are fixed ratios of V
DD.
Their ranges never overlap.
Note 7: Tested with I
CSOUT
= -1mA.
Note 8: Gain tested with 1mV step with I
CSOUT
= -1mA.
Figure 1. Block Diagram
+
-
State Machine
Voltage
and
Temperature
Measurement
Charge
Timer
BIAS
VP1
CC2
LED1
TMR
VDD
VSS
LED2
VP2
THM1
THM2
Cell
Test
CTST
CC1
CSOUT
0.125V
DMSEL
SUSPEND
3.7V
UVLO
Oscillator
+
-
VN0
Presence Test
Pre-Charge
Fast Charge
&
Cell Tests
Top-Off Charge
Maintenance Charge
Charge
Mode
Select
VN1
+
-
I
PTST
I
PTST
0.1V
DS2712
DS2711