LT1072CN8 Datasheet, PDF (6/16 Pages) Linear Technology – 1.25A High Efficiency Switching Regulator

LT1072
TYPICAL PERFOR A CE CHARACTERISTICS
Transconductance of Error
Amplifier
7000
–30
6000
5000
θ
0
30
4000
60
3000
G_m
90
2000
120
1000
150
0
180
–1000
1k
10k
100k
1M
FREQUENCY (Hz)
210
10M
LT1072 • TPC19
V_C Pin Characteristics
300
200 ^{VFB = 1.5V (CURRENT INTO VC PIN)}
100
0
–100
T_J = 25°C
–200
–300
V_FB = 0.8V (CURRENT OUT OF V_C PIN)
– 400
0
0.5 1.0 1.5 2.0 2.5
V_C PIN VOLTAGE (V)
LT1072 • TPC20
Switch “Off” Characteristics
1000
900
800
700
V_SUPPLY = 55V
600
VSUPPLY = 40V
500
VSUPPLY = 15V
VSUPPLY = 3V
400
300
200
100
0
0 10 20 30 40 50 60 70 80 90 100
SWITCH VOLTAGE (V)
LT1072 • TPC21
BLOCK DIAGRA
V_IN
2.3V
REG
SWITCH
16V
OUT
FLYBACK
ERROR
AMP
40kHz
OSC
LOGIC
DRIVER
6
MODE
SELECT
FB
–
ERROR
AMP
+
1.24V
REF
COMP
ANTI-
SAT
V_C
SHUTDOWN
CIRCUIT
CURRENT
AMP
0.16Ω
0.16Ω
GAIN
≈6
E1* E2
0.15V * ALWAYS CONNECT E1 TO GROUND PIN ON MINIDIP AND SURFACE MOUNT
PACKAGES. EMITTERS TIED TO GROUND ON TO-3 AND TO-220 PACKAGES
GND
LT1072 • BD01
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