Pin Functions

Timing chart for pin switching operations during PWM drive

Figure 1 Switching Waveforms

toff: Output off time. Determined by external capacitor and resistor Ct and Rt. (toff = Ct

× Rt)

td: Delay time between the point the set current is sensed at the SENSE pin and the point the output turns off.

No. 5505-4/7

LB1845

Pin no.

Pin

Function

1, 14

Output stage power-supply voltage

2

SENSE1

Set current detection pins.

13

SENSE2

Connect these pins, fed back through noise filters, to E1 and E2.

3

E1

The set current is controlled by the resistors Re inserted between these pins and ground.

12

E2

4, 11

D-GND

Internal diode anode connection

6

OUT 1B

Outputs

7

OUT 1A

8

OUT 2B

9

OUT 2A

15

GND

Ground

27

RC1

Used to set the output off time for the switched output signal.

16

RC2

The fixed off times are set by the capacitors and resistors connected to these pins. toff = CR.

26

Output current settings

17

The output current is determined by the voltage (in the range 1.5 to 7.5 V) input to these pins.

25

PHASE1

Output phase switching inputs.

18

PHASE2

High-level input: OUT A = high, OUT B = low

Low-level input: OUT A = low, OUT B = high

24

ENABLE1

Output on/off settings

19

ENABLE2

High-level input: output off

Low-level input: output on

22, 23

I01, I11

Digital inputs that set the output current

21, 20

I02, I12

The output currents can be set to 1/3, 2/3, or full by setting these pins to appropriate combinations of high and low levels.

28

Logic block power supply