SWITCHED-MODE DUAL VOLTAGE REGULATOR

Rev D1, Page 2/12

DESCRIPTION

The device iC-WD is a monolithic switching regula-

tor with two downstream 5 V resp. 3.3 V linear reg-

ulators. In view of the high efficiency of the down

converter for an input voltage range of 8 to 36 V, the

iC-WD family is well-suited for industrial applications

which require a stabilised 5 V resp. 3.3 V power sup-

ply with minimal power dissipation and few compo-

nents.

Switching transistor, free-wheeling diode and oscil-

lator are integrated, limiting the necessary external

elements for the switching regulator to the inductor,

the back-up capacitor and one resistor. This resistor

determines the regulator’s cut-off current and thus its

efficiency in the particular application at hand.

The downstream linear regulators feature a low resid-

ual ripple even with relatively small smoothing capac-

itors in the µF range. The output voltages have an

internal reference and are specified ±5% in the en-

tire operating and temperature range. The use of two

mutually independent linear regulators makes it pos-

sible to isolate the voltage supply of sensitive ana-

logue circuits or sensors from the supply for digital

and driver devices.

The chip temperature and the output voltages are

monitored. A fault is signalled via the current-limited

open-collector output NER, for example by an LED

display or a logical link with other error signals from

the system.

In the event of overtemperature, the

switching regulator is disabled to reduce the power

dissipation of the chip.

PACKAGES SO8, SO8tp, DFN10 to JEDEC Standard

PIN CONFIGURATION SO8, SO8tp

(top view)

1

VHL

GND

VBR

NER

2

3

4

VCC

VH

VCCA

VB

8

7

6

5

PIN FUNCTIONS

No. Name Function

1 NER

Error Output

2 VBR

Pin for shunt

3 VHL

Pin for inductor

4 GND

Ground (reference voltage)

5 VH

Intermediate Voltage

6 VCC

Output (200 mA)

7 VCCA Output (25 mA)

8 VB

Supply Voltage

The Thermal Pad (optional) is to be connected to a Ground Plane on the PCB.

PIN CONFIGURATION DFN10

(top view)

5

2

1

3

4

7

8

6

9

10

...

...yyww

iC−WDx

PIN FUNCTIONS

No. Name Function

1 NER

Error Output

2 n.c.

3 VBR

Pin for shunt

4 VHL

Pin for inductor

5 GND

Ground (reference voltage)

6 GND

Ground (reference voltage)

7 VH

Intermediate Voltage

8 VCC

Output (200 mA)

9 VCCA Output (25 mA)

10 VB

Supply Voltage

The Thermal Pad is to be connected to a Ground Plane on the PCB.

Orientation of the package label (

WDx ...yyww) may vary.