Symbol

Parameter

Test Condition

Min.

Typ.

Max.

Unit

CURRENT SENSE DISCONNECTION

VCSD

Current sense disconnection

threshold

Voltage rising

165

200

235

mV

TCSD_DB

Disconnection

debounce time

8

10

12

µs

EQUIVALENT MULTIPLIER

KM

Equivalent multiplier gain

VHVPK < 200 V(1)

0.405

0.44

0.475

V/V

VHVPK > 235 V(1)

0.092

0.10

0.108

V/V

THD CCM-OPTIMIZER

KCCM

0.51

0.55

0.59

H

FEEDBACK FAILURE PROTECTION/EXTERNAL BURST MODE (EBM)

VFB_FF/EBM

Feedback failure protection

(on FB) / External burst mode

threshold

Voltage falling(1)

460

500

540

mV

Hysteresis

50

mV

TFF/EBM_DB

FFP/EBM debounce time

1.25

1.8

2.35

µs

IFB_EBM

FB current during EBM

VFB < VFB_FF/EBM

70

100

135

µA

FB current at exit EBM

VFB_FF/EBM < VFB < VREF

0.75

1

1.25

mA

SWITCHING FREQUENCY

FSW

Switching frequency

(L4985A)

TON = 9µs, VHVPK < 200 V

60

65

71

kHz

TON = 3µs, VHVPK > 235 V

Switching frequency

(L4985B)

TON = 4.5µs, VHVPK < 200 V

120

130

142

kHz

TON = 1.5µs, VHVPK > 235 V

MAXIMUM ON-TIME

TON_MAX

Maximum on-time

L4985A

32

40

50

µs

L4985B

16

20

26

µs

MINIMUM OFF-TIME

TOFF_MIN

Minimum off-time

L4985A

0.75

1.0

1.35

µs

L4985B

0.35

0.5

0.75

µs

GATE DRIVER

VOL

Output low voltage

Isink = 200 mA

0.7

V

Isink = 5 mA

0.02

V

VOH

Output high voltage

15V<VCC<24.5 V, Isource = 5 mA

11

12

13

V

VCC = 9 V, Isource = 5 mA

7.85

V

Isrcpk

Peak source current

-0.7

A

Isnkpk

Peak sink current

1.5

A

tf

Voltage fall time

VGD from 8 V to 1 V

3

7

15

ns

tr

Voltage rise time

VGD from 1 V to 8 V

5

10

15

ns

UVLO saturation

VCC = 0 V to VCC_ON, Isink = 1 mA

1.1

V

1. Parameters tracking each other.

2. The VCC pin is self-limited by an internal clamp when the device is in switching modality.

3. Equivalent to just before burst-mode condition.

4. Equivalent to full-load condition.

L4985

Electrical characteristics

DS13769 - Rev 3

page 9/27