LB8650T

No.7895-4/6

Application Example

(1) Solenoid (constant current drive), stepping motor (constant voltage drive)

Timing chart for solenoid SH

(1) ICI pin voltage is set to 0V in shutter ready mode of *LLLH input.

(2) At *LLHH input, solenoid is driven by constant current control. The ICI pin input voltage is set with the decay

time constant to be larger than the coil decay time constant by using the external CR and the rise correction

occurs with respect to the coil wave. By doing this, stable shutter operation can be carried out with respect to the

power source variations.

(Note) ICI pin rise compensation is made without C1 and the rise waveform of coil current is made at decrease of VB

power. C1 is set to the time constant lower than this waveform.

(3) At *HLHH input, solenoid current is controlled by 2/3, and it becomes HOLD state.

• Constant current value setting: ICI voltage/Rf

(Note1) Consider the FC capacitor between 0.01 to 0.1

µF to set the capacitance value that ensure no oscillation

problem at transfer to the HOLD mode. In particular, the solenoid with high inductance should have an

allowance for capacitance.

Vref

R1

ICI

R2

C1

FC

0.01 to 0.1

µF

RFG

Rf

SH/SOL

OUT5N

VB

VC1

P-GND

VB

OUT1

OUT2

OUT4

OUT3

AF/STP

0.01

µF

ILB01606

ICI

Rise correction

VB is high. (Without C1)

SH

preparing

SH closing operation

SH closing HOLD

VB is low. (Without C1)

Rise correction coil current

SOL/IO

ILB01607