9-25

HIP1090

Figure 3 shows the pulsed output switching characteristics

of the HIP1090 as a high side driver. A small delay step is

level of the PNP pass transistor and controls the drive as a

ratio of load current. As the load current is reduced, the drive

current to the output transistor is reduced. Under low current

operation, the saturation level is controlled and the turn-OFF

switching time is much faster. The control switching element

is shown as a 2N5320 NPN transistor but may be any open

collector or MOS gate. A pull-up resistor of 2k

Ω is used for a

slight improvement in the turnoff fall time but is not an

with a mechanical switch or may be controlled from any

driver output that can sink the worst case condition of pin 2

(typically 50mA).

FIGURE 3. TYPICAL ON-OFF SWITCHING CHARACTERISTIC

OF THE HIP1090 USING AN NPN TRANSISTOR TO

HIP1090

+16V

1k

Ω

2k

Ω

2N5320

(CONTROL PIN)

(OUTPUT)

(SUPPLY INPUT)

OR EQUIVALENT

15

µs

15

µs

15

10

5

0

ON

OFF

ON

OFF

24

Ω

OPTIONAL

The circuit of Figure 4 shows how the HIP1090 transient

suppression voltage shutdown threshold may be increased

tor terminal of the transistor switch. The preferred method is

to use a zener diode for a fixed level shift. While a resistor in

place of the zener diode having the same voltage drop will

cause variations of the Over-Voltage Shutdown Threshold.

In this circuit, a 10V zener provides a typical over-voltage

threshold shift to ~27V. The threshold for over-voltage shut-

FIGURE 4. A TYPICAL APPLICATION CIRCUIT THAT USES A

RAISE

THE

OVER-VOLTAGE

SHUTDOWN

THRESHOLD

Also, it is important to note that high peak current values

may be reached when driving nonlinear and inductive loads.

The peak output current of the HIP1090 is self limiting in the

1A to 2A range to protect against short circuit conditions.

Sustained high peak current may increase the junction tem-

happens, the output current will fall off briefly before recover-

ing, unless the over-temperature condition is sustained.

Internally, both input and output over-voltage conditions are

sensed to protect the circuit, making the high levels of tran-

sient voltage ratings possible. Sustained voltage ratings of

±24VDC with transient ratings to ±90V allow a wide variety

of applications in high stress environments.

higher current version of the CA3273 high side driver, which

turns-on without the delayed step on the leading edge of the

The CA3273 has a higher transient suppression threshold.

HIP1090

+24V

1k

Ω

2N5320

(OUTPUT)

(SUPPLY INPUT)

OR EQUIVALENT

ON

OFF

24

Ω

10V

2k

Ω

OPTIONAL