Pin Description
Pin No.
Pin
Pin voltage
LB11880
Function
Equivalent circuit
VREG
1
FC
Frequency characteristics compensation
Oscillation in the current control system closed
loop can be prevented by connecting a capacitor
between this pin and ground.
1 kΩ
1
10 kΩ 5 kΩ
Speed control
2
VC
0 V to VREG This circuit implements constant-current control in
which current feedback is applied from the RF
system.
V CC
VREG
50 µA 50 µA
27 kΩ
40 kΩ
2
200 Ω
24 kΩ
Control system power supply
3
VREG
4 V to 6 V This power supply must be stabilized so that ripple
and noise do not enter the IC.
4
PGIN+
PG amplifier plus side input
This pin is biased to 1/2 VREG internally.
6 µA 6 µA 6 µA
VREG
10 kΩ
5
PGIN–
PG amplifier minus side input
6
PGOUT1
PG amplifier linear output
200 Ω
5
60 µA
38 Ω
38 Ω
200 Ω
4
10 kΩ
VREG
30 µA
6
5 kΩ
5 kΩ
4
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