LTC4008_15 Datasheet, PDF (4/24 Pages) Linear Technology – 4A, High Effi ciency, Multi-Chemistry Battery Charger

LTC4008
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_DCIN = 20V, V_BAT = 12V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Input P-Channel FET Driver (INFET) (LTC4008 Only)
DCIN Detection Threshold (V_DCIN – V_CLP)
Forward Regulation Voltage (V_DCIN – V_CLP)
Reverse Voltage Turn-Off Voltage (V_DCIN – V_CLP)
INFET “On” Clamping Voltage (V_CLP – V_INFET)
INFET “Off” Clamping Voltage (V_CLP – V_INFET)
Thermistor
DCIN Voltage Ramping Up
from V_CLP – 0.1V
DCIN Voltage Ramping Down
I_INFET = 1μA
I_INFET = –25μA
l0
0.17 0.25
V
l
25
50
mV
l –60 –25
mV
l5
5.8
6.5
V
0.25
V
NTCVR Reference Voltage During Sample Time
4.5
V
High Threshold
V_NTC Rising
l NTCVR NTCVR NTCVR
V
• 0.48 • 0.5 • 0.52
Low Threshold
V_NTC Falling
l NTCVR NTCVR NTCVR
V
• 0.115 • 0.125 • 0.135
Thermistor Disable Current
Indicator Outputs (ACP/SHDN, FLAG, I_CL, FAULT
C10TOL FLAG (C/10) Accuracy
V_NTC ≤ 10V
Voltage Falling at PROG
10
μA
l 0.375 0.397 0.420
V
I_CL Threshold Accuracy
V_OL
Low Logic Level of ACP/SHDN, FLAG, I_CL, FAULT
V_OH
High Logic Level of ACP/SHDN, I_CL
I_OFF
Off State Leakage Current of FLAG, FAULT
I_PO
Pull-Up Current on ACP/SHDN, I_CL
Oscillator
V_CLP – V_CLN
I_OL = 100μA
I_OH = –1μA
V_OH = 3V
V = 0V
83
93
105
mV
0.5
V
l 2.7
V
–1
1
μA
–10
μA
f_OSC
Regulator Switching Frequency
f_MIN
Regulator Switching Frequency in Drop Out
DC_MAX Regulator Maximum Duty Cycle
Gate Drivers (TGATE, BGATE)
Duty Cycle ≥ 98%
V_CSP = V_BAT
255 300
345
kHz
20
25
kHz
98
99
%
TGTR
TGTF
BGTR
BGTF
V_TGATE High (V_CLP – V_TGATE)
V_BGATE High
V_TGATE Low (V_CLP – V_TGATE)
V_BGATE Low
TGATE Transition Time
TGATE Rise Time
TGATE Fall Time
BGATE Transition Time
BGATE Rise Time
BGATE Fall Time
V_TGATE at Shutdown (V_CLP – V_TGATE)
V_BGATE at Shutdown
I_TGATE = –1mA
C_LOAD = 3000pF
C_LOAD = 3000pF
I_BGATE = 1mA
C_LOAD = 3000pF, 10% to 90%
C_LOAD = 3000pF, 10% to 90%
C_LOAD = 3000pF, 10% to 90%
C_LOAD = 3000pF, 10% to 90%
I_TGATE = –1μA, DCIN = 0V, CLP = 12V
I_BGATE = 1μA, DCIN = 0V, CLP = 12V
50
mV
5.6
10
V
5.6
10
V
50
mV
50
110
ns
50
100
ns
40
90
ns
40
80
ns
100
mV
100
mV
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: See Test Circuit.
Note 3: Does not include tolerance of current sense resistor or current
programming resistor.
Note 4: The LTC4008E is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 5: Voltage accuracy includes BATMON error and voltage reference
error. Does not include error of external resistor divider.
4008fb
4