• Output transistors

The output transistors must be chosen according to the current and breakdown voltage settings determined by the

required motor power. Printed circuit board space considerations determine the choice of discrete or driver array

components.

The 2SC4070 (SPA) and 2SC4113 (SPA) lower side predriver transistors include an emitter-base resistor.

When no resistor is required, the same transistors as used in the output interface can be used.

Driver arrays:

SLA6022 and SLA6023 (Sanken)

12. Through currents due to the direct PWM technique

In the direct PWM technique through currents flow in the outputs due to the switching, e.g., when used in a discrete

structure (including predriver circuits) or in LB1822 applications. These through currents are due to the delays and

parasitic capacitances in the output transistors. Although additional capacitors were previously used to deal with this

problem, the LB1823 includes circuit modifications to ameliorate through currents. However, even despite these

measures, through currents can still occur if the values of R17, R18 and R19 are made too large, since the switching

waveform during switching, this will not be a problem. (These occur in the probe and do not correspond to current

flows.)

13. Oscillator element

Normally, a crystal resonator, a resistors, and two capacitors are connected to the LB1823 Xtal pin. A ceramic

oscillator could also be used in applications that do not require such precise speed control characteristics. To avoid

problems, consult with the manufacturer of the oscillator element when selecting the oscillator element and the

values of the external resistor and capacitors used. Use a circuit consisting of resistors and a pnp transistor as shown

in the figure to apply an external clock signal (CLK) to the Xtal pin.

Input signal levels

High level voltage: 4.0 V minimum

Low level voltage: 1.5 V maximum

Capacitors must be added to this circuit if overshoot

and/or undershoot appears in the input waveform. Be

sure to check for this condition in that case.

Reference values

No. 4263-10/11

LB1823

Upper side transistors

Lower side transistors

Current

Breakdown voltage

(Darlington)

2SA1259

2SD1060

5 A

50 V

2SB881

2SD1061

7 A

50 V

2SB882

2SD1062

10 A

50 V

2SB883

2SD1065

15 A

50 V

Ra = 1.5 k

Ω

Rb = 2.0 k

Ω

Ra = 2.0 k

Ω

Rb = 1.0 k

Ω