ISL6719

FN6555 Rev 2.00

Page 6 of 9

July 15, 2014

Pin Descriptions

VPWR

VPWR is the power connection for the IC. UVLO

enables/disables the output and places the device into a

standby mode even if AUXIN is externally biased.

To optimize noise immunity, bypass VPWR to GND with a

ceramic capacitor as close to the VPWR and GND pins as

possible.

AUXIN

This is the input for an external bias source typically provided

by an auxiliary transformer winding. This input is not required

and may be grounded or left open. Maximum input bias is 40V.

ENABLE

The positive logic on/off control input. A logic high enables

VSW. Asserting this signal low turns off VSW. ENABLE and

ENABLE_N are logically ORed. Either signal can enable VSW,

but both must be false to disable VSW.

ENABLE_N

The negative logic on/off control input. A logic low enables

VSW. Asserting this signal high turns off VSW. ENABLE and

ENABLE_N are logically ORed. Either signal can enable VSW,

but both must be false to disable VSW.

GND

Signal and power ground connections for this device.

VSW

This is the switched regulated low voltage output supply that is

derived from VPWR or AUXIN. Its output is adjustable from

1.5V to 20V using an appropriate divider from VSW to VSW_FB.

Protection circuitry prevents the output from exceeding 25V in

the event of a fault on VSW_FB (short high or low). The

minimum output current capability is 100mA. VSW requires a

minimum load of 3mA.

VSW_FB

The feedback pin for VSW. A divider from VSW to ground sets

feedback for VSW and determines the output voltage.

Typical Performance Curves

FIGURE 3. VSW REGULATION vs TEMPERATURE @ VPWR = 100V,

FIGURE 4. VSW REGULATION vs LOAD @ VPWR = 18V,

AUXIN = 15V, +25°C

0

20

40

60

80

100

3.0

3.5

4.0

4.5

5.0

5.5

VSW CURRENT (mA)

0

20

40

60

80

100

1.0

1.5

2.0

2.5

VSW CURRENT (mA)

-40

-25

-10

5

20

35

50

65

80

95

110

0.997

0.998

0.999

1.000

1.001

1.002

VSW = 1.5V, AUXIN = 15V

TEMPERATURE (°C)

VSW = 5V, AUXIN = 15V

VSW = 20V, AUXIN = 30V

VSW = 12V, AUXIN = 15V

VSW = 15V, AUXIN = 30V

0

10

20

30

40

50

60

70

80

90

100

0.9990

0.9995

1.0000

1.0005

1.0010

VSW = 12V

LOAD (mA)

VSW = 10V

VSW = 5V