Datasheet

LTC4100
3
4100fc
For more information www.linear.com/LTC4100
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
DD
= 3.3V, V
BAT
= 12V unless otherwise noted. (Note 4)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Current Sense Amplifier, CA1
Input Bias Current into BAT Pin 11.66 µA
CMSL CA1/I
1
Input Common Mode Low
●
0 V
CMSH CA1/I
1
Input Common Mode High V
DCIN
≤ 28V
●
V
CLN
–0.2 V
Current Comparators I
CMP
and I
REV
I
TMAX
Maximum Current Sense Threshold (V
CSP
–V
BAT
) V
ITH
= 2.5V
●
140 165 200 mV
I
TREV
Reverse Current Threshold (V
CSP
–V
BAT
) – 30 mV
Current Sense Amplifier, CA2
Transconductance 1 mmho
Source Current Measured at I
TH
, V
ITH
= 1.4V –40 µA
Sink Current Measured at I
TH
, V
ITH
= 1.4V 40 µA
Current Limit Amplifier
Transconductance 1.5 mmho
V
CLP
Current Limit Threshold
●
93 100 107 mV
I
CLN
CLN Input Bias Current 100 nA
Voltage Error Amplifier, EA
Transconductance 1 mmho
Sink Current Measured at I
TH,
V
ITH
= 1.4V 36 µA
OVSD Overvoltage Shutdown Threshold as a Percent of
Programmed Charger Voltage
●
102 107 110 %
Input P-Channel FET Driver (INFET)
DCIN Detection Threshold (V
DCIN
–V
CLP
) DCIN Voltage Ramping Up from V
CLP
–0.05V
●
0 0.17 0.25 V
Forward Regulation Voltage (V
DCIN
–V
CLP
)
●
25 50 mV
Reverse Voltage Turn-Off Voltage (V
DCIN
–V
CLP
)
●
–60 –25 mV
INFET ON Clamping Voltage (V
DCIN
–V
INFET
) I
INFET
= 1µA
●
5 5.8 6.5 V
INFET OFF Clamping Voltage (V
DCIN
–V
INFET
) I
INFET
= –25µA 0.25 V
Oscillator
f
OSC
Regulator Switching Frequency 255 300 345 kHz
f
MIN
Regulator Switching Frequency in Drop Out Duty Cycle ≥ 98% 20 25 kHz
DC
MAX
Regulator Maximum Duty Cycle V
CSP
= V
BAT
98 99 %
Gate Drivers (TGATE, BGATE)
V
TGATE
High (V
CLP
-V
TGATE
) I
TGATE
= –1mA 50 mV
V
BGATE
High C
LOAD
= 3000pF 4.5 5.6 10 V
V
TGATE
Low (V
CLP
-V
TGATE
) C
LOAD
= 3000pF 4.5 5.6 10 V
V
BGATE
Low I
BGATE
= 1mA 50 mV
TGTR
TGTF
TGATE T
ransition Time
TGATE Rise Time
TGATE Fall Time
C
LOAD
= 3000pF, 10% to 90%
C
LOAD
= 3000pF, 10% to 90%
50
50
110
100
ns
ns
BGTR
BGTF
BGATE T
ransition Time
BGATE Rise Time
BGATE Fall Time
C
LOAD
= 3000pF, 10% to 90%
C
LOAD
= 3000pF, 10% to 90%
40
40
90
80
ns
ns
V
TGATE
at Shutdown (V
CLN
-V
TGATE
) I
TGATE
= –1µA 100 mV
V
BGATE
at Shutdown I
TGATE
= 1µA 100 mV