DS2731
Cache-Memory Battery-Backup Management IC
_______________________________________________________________________________________ 5
THERMAL PROTECTION CHARACTERISTICS
(V
IN
= +10.8V to +13.2V, T
A
= -20°C to +70°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
THM Pin Internal Pullup Voltage V
THM
(Notes 1, 12) V
CBIAS
V
THM Pin Internal Resistance R
THM
THM to C
BIAS
(Note 12) 9.8 10.0 10.2 k
Thermistor Overtemperature
HALT Threshold
V
HOT
(Notes 12, 13) 0.271 0.283 0.292
Ratio to
V
CBIAS
Thermistor Overtemperature
Resume Threshold
V
HYS-HOT
(Notes 12, 13) 0.3055
Ratio to
V
CBIAS
Thermistor Undertemperature
HALT Threshold
V
COLD
(Notes 12, 13) 0.727 0.739 0.748
Ratio to
V
CBIAS
Thermistor Undertemperature
Resume Threshold
V
HYS-COLD
(Notes 12, 13) 0.714
Ratio to
V
CBIAS
Thermistor Disable
Threshold
V
DISABLE
(Notes 12, 13) 0.02 0.03 0.04
Ratio to
V
CBIAS
Internal Overtemperature
Protection Threshold CCCV
T
PROTECT_CCCV
(Note 12) 160 °C
Internal Overtemperature
Hysteresis CCCV
T
HYS-PROTECT_CCCV
(Note 12) -20 °C
Internal Overtemperature
Protection Threshold MEM_REG
T
PROTECT_MEMREG
(Note 14) 165 °C
Internal Overtemperature
Hysteresis MEM_REG
T
HYS-PROTECT_
MEMREG
(Note 14) -15 °C
Charging Current Reduction
Threshold
T
CHOKE
(Note 12) 100 °C
Charging Current Reduction Rate T
CHOKE_RATE
(Note 12) 133 mA/°C
Note 1: All voltages referenced to AGND pin.
Note 2: V
CIN
is equivalent to V
AUX
when V
AUX
is greater than V
TRIP
, otherwise V
CIN
is equivalent to V
BATT+
.
Note 3: Supply-current specification is only for current drain of the IC and does not include cell-charge current, load-supply cur-
rent, or any external resistor bias currents. The only exception is I
SLEEP
, which does account for complete current drain of
the lithium cell during low-battery conditions.
Note 4: Below this voltage, the input is guaranteed to be logic-low.
Note 5: Operating from 3.3V ±10%.
Note 6: Above this voltage, the input is guaranteed to be logic-high.
Note 7: Assumes an R
SNS
value of 0.05Ω.
Note 8: Relative to V
CV
.
Note 9: With recommended application circuit.
Note 10: Includes complete package resistance.
Note 11: This specification is from the rising or falling edge of ENS to the closure of the switch and includes whatever delay is in the
internal logic and FET drivers.
Note 12: Applies to charger.
Note 13: Multiply these values by C
BIAS
voltage to get value in volts. Recommended value of resistor in divider network is 10kΩ ±1%.
Tolerance includes tolerances of internal resistance and C
BIAS
voltage.
Note 14: Applies to memory buck regulator.
