Datasheet

LT3469
4
3469f
TYPICAL PERFOR A CE CHARACTERISTICS
UW
V
CC
Quiescent Current
Output Current
vs Differential Input Voltage
V
CC
(V)
15 18
0
I
Q
(mA)
1.0
2.5
21
27
30
3469 G01
0.5
2.0
100°C
25°C
–50°C
1.5
24
33
36
DIFFERENTIAL INPUT VOLTAGE (mV)
–50
OUTPUT CURRENT (mA)
0
10
20
30
30
3469 G02
–10
–20
–5
5
15
25
–15
–25
–30
–30
–10
10
–40 40
–20
0
20
50
100°C
–50°C
25°C
(g
m
Amplifier)
g
m
vs V
CC
V
CC
(V)
15
g
m
(µA/mV)
100
150
35
3469 G14
50
0
20
25
30
250
200
–50°C
25°C
100°C
UU
U
PI FU CTIO S
OUT (Pin 1): Output of the g
m
Amplifier. There must be at
least 5nF of capacitive load at the output in a gain of 10
configuration. Capacitive loads up to 300nF can be con-
nected to this pin. Piezo actuators below 5nF can be driven
if capacitance is placed in parallel to bring the total
capacitance to 5nF.
FB (Pin 2): Feedback Pin. Reference voltage is 1.23V.
Connect feedback resistor divider here.
V
IN
(Pin 3): Input Supply Pin. Must be locally bypassed.
GND (Pin 4): Ground Pin. Connect directly to local ground
plane.
SW (Pin 5): Switch Pin. Connect inductor here. Minimize
trace area at this pin to reduce EMI.
V
CC
(Pin 6): Output of Switching Regulator and Supply
Rail for g
m
Amp. There must be 0.22µF or more of
capacitance here.
+IN (Pin 7): Noninverting Terminal of the g
m
Amplifier.
–IN (Pin 8): Inverting Terminal of the g
m
Amplifier.
BLOCK DIAGRA
W
–
+
SW
4
5
V
CC
2
FB
1.23V
7
1
V
IN
V
CC
+IN
–IN
OUT
GND
3469 F01
Q1
A1
SWITCH
CONTROLLER
6
V
IN
3
–
+
8
g
m
Figure 1. LT3469 Block Diagram