Datasheet
4
LT1769
1769fa
ELECTRICAL CHARACTERISTICS
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
Efficiency of Figure 1 Circuit
I
BAT
(A)
0.2
EFFICIENCY (%)
100
98
96
94
92
90
88
86
84
82
80
1.0 1.8 2.2
1769 G01
0.6 1.4
V
IN
= 16.5
V
BAT
= 8.4V
CHARGER EFFICIENCY
INCLUDES LOSS
IN DIODE D3
V
CC
(V)
0
I
CC
(mA)
7.0
6.5
6.0
5.5
5.0
4.5
5
10 15 20
1769 G03
25 30
T
J
= 125°C
T
J
= 25°C
T
J
= 0°C
MAXIMUM DUTY CYCLE
I
CC
vs Duty Cycle
DUTY CYCLE (%)
010305070
I
CC
(mA)
80
1769 G02
20
40
60
8
7
6
5
4
3
2
1
0
T
J
= 125°C
T
J
= 0°C
T
J
= 25°C
V
CC
= 16V
I
CC
vs V
CC
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 16V, V
BAT
= 8V. No load on any outputs unless otherwise noted.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Tested with Test Circuit 1.
Note 3: Tested with Test Circuit 2.
Note 4: A linear interpolation can be used for reference voltage
specification between 0°C and –40°C.
PARAMETER CONDITIONS MIN TYP MAX UNITS
Voltage Amplifier VA
Transconductance (Note 3) Output Current from 50µA to 500µA 0.25 0.6 1.3 mho
Output Source Current V
OVP
= V
REF
+ 10mV, V
PROG
= V
REF
+ 10mV 1.1 mA
OVP Input Bias Current VA Output Current at 0.5mA
● ±3 ±10 nA
VA Output Current at 0.5mA, T
A
> 90°C ● –15 25 nA
VA Output Current at 0.5mA, T
A
< 0°C ±15 nA
Current Limit Amplifier CL1, 8V
≤
Input Common Mode
Turn-On Threshold 0.5mA Output Current 93 100 110 mV
Transconductance Output Current from 50µA to 500µA 0.5 1 2 mho
CLP Input Current 0.5mA Output Current, V
UV
≥ 0.4V 0.3 1 µA
CLN Input Current 0.5mA Output Current V
UV
≥ 0.4V 0.8 2 mA