NCP1032

www.onsemi.com

3

Table 1. FUNCTIONAL PIN DESCRIPTION

Pin

Name

Function

Description

1

GND

IC Ground

Ground reference pin for the circuit.

2

Oscillator Frequency

Selection

An external capacitor connected to this pin sets the oscillator frequency up to 1 MHz. The

oscillator can be synchronized to a higher frequency by charging or discharging CT to trip the

internal 3.0 V/3.5 V comparators. If a fault condition exists, the power switch is disabled and

the frequency is reduced.

3

Feedback Signal Input

The regulated voltage is scaled down to 2.5 V by means of a resistor divider. Regulation is

achieved by comparing the scaled voltage to an internal 2.5 V reference.

4

COMP

Error Amplifier

Compensation

The output of the internal error amplifier. External compensation network between COMP

and VFB pin is required for stable operation.

5

CL

Current Limit Threshold

Selection

current limit. If the CL pin is left open, the current limit value is set to its initial maximum value

internal soft−start feature effectively limits the primary transformer high current peaks during

startup phase.

6

UV/OV

Input Line Undervoltage

and Overvoltage

Shutdown

Input line voltage is scaled down using an external resistor divider. The minimum operating

Vin voltage is achieved when the voltage on UV/OV pin reaches UV threshold 1.0 V. The

maximum operating voltage is then limited by 2.4 V on UV/OV pin. A device version without

OV protection feature is available, see ordering information section.

7

Powers the Internal

Circuitry

Supplies power to the internal control circuitry. Connect an external capacitor for energy

storage during startup. The Vcc voltage should not exceed 16 V during operation.

8

Drain Connection

Connects the power switch and startup circuit to the primary transformer windings.

EP

EP

Thermal Flag

This is the thermal flag for the IC and should be soldered to the ground plane.

Table 2. MAXIMUM RATINGS

Rating

Symbol

Value

Unit

Power Switch and Startup Circuits Voltage

BVdss

−0.3 to +200

V

VCC Power Supply Voltage

−0.3 to +16

V

Power Supply Voltage on all Pins, except VDRAIN and VCC

−0.3 to +10

V

Drain Current Peak During Transformer Saturation

1.0

A

Thermal Resistance Junction−to−Air –W DFN8 3x3, case 511BH

(100 sq mm, 2oz) (Note 4)

(500 sq mm, 2oz) (Note 4)

(100 sq mm,2oz,) (Note 5)

109

64

44

°C/W

Maximum Junction Temperature

150

°C

Storage Temperature Range

−60 to +150

°C

ESD Capability, Human Body Model Pins 1−7 (Note 1)

4.0

kV

ESD Capability, Machine Model Pins 1−7 (Note 1)

400

V

Pin 8 is connected to the high voltage startup and power switch which is protected to

the maximum drain voltage

200

V

Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality

should not be assumed, damage may occur and reliability may be affected.

1. This device series contains ESD protection and passes the following tests:

Human Body Model (HBM)

± 2.0 kV per JEDEC standard: JESD22−A114.

Machine Model (MM)

± 200 V per JEDEC standard: JESD22−A115.

2. This device contains latch−up protection and it exceeds

± 100 mA per JEDEC standard: JESD78 class II

3. Moisture Sensitivity Level (MSL): 1 per IPC/JEDEC standard: J−STD−020A

4. EIA JEDEC 51.3, single layer PCB with added heat spreader

5. EIA JEDEC 51.7, four layer PCB with added heat spreader