Datasheet

LTC3788-1
8
37881fc
TEMPERATURE (°C)
–45
SENSE CURRENT (µA)
5
55
80
0
80
40
160
200
240
120
20
100
60
180
220
260
140
–20
30
105
130
37881 G22
SENSE
+
PIN
SENSE
–
PIN
V
SENSE
= 12V
SENSE Pin Input Current
vs Temperature
SENSE Pin Input Current
vs V
SENSE
Voltage
SENSE Pin Input Current
vs I
TH
Voltage
TYPICAL PERFORMANCE CHARACTERISTICS
I
TH
VOLTAGE (V)
0
SENSE CURRENT (µA)
1
2
2.5
0
80
40
160
200
240
120
20
100
60
180
220
260
140
0.5
1.5
3
37881 G23
SENSE
+
PIN
SENSE
–
PIN
V
SENSE
= 12V
V
SENSE
COMMON MODE VOLTAGE (V)
2.5
SENSE CURRENT (µA)
17.5
27.5
32.5
0
80
40
160
200
240
120
20
100
60
180
220
260
140
7.5 12.5
22.5
37.5
37881 G24
SENSE
+
PIN
SENSE
–
PIN
ITH1, ITH2 (Pin 1, Pin 13): Current Control Threshold
and Error Amplifier Compensation Point. The voltage on
this pin sets the current trip threshold.
VFB1, VFB2 (Pin 2, Pin 12): Error Amplifier Feedback
Input. This pin receives the remotely sensed feedback
voltage from an external resistive divider connected across
the output.
SENSE1
+
, SENSE2
+
(Pin 3, Pin 11): Positive Current
Sense Comparator Input. The (+) input to the current
comparator is normally connected to the positive terminal
of a current sense resistor. The current sense resistor is
normally placed at the input of the boost controller in
series with the inductor. This pin also supplies power to
the current comparator.
DUTY CYCLE (%)
0
MAXIMUM CURRENT SENSE VOLTAGE (mV)
80
100
70
60
40
20 40
10 90
30 50
80
60 100
20
0
120
37881 G25
OPERATING FREQUENCY (kHz)
50
0
CHARGE PUMP CHARGING CURRENT (µA)
20
30
80
50
250 450 550
10
60
70
40
150 350 650 750
37881 G26
T = 130°C
T = 25°C
T = –45°C
V
SW
= 12V
V
BOOST
– V
SW
= 4.5V
Maximum Current Sense
Threshold vs Duty Cycle
Charge Pump Charging Current
vs Operating Frequency
PIN FUNCTIONS