ISL78227

FN8808 Rev.6.02

Page 12 of 43

Feb 28, 2025

Duty Cycle Matching

VRSENx = 30mV, RSETx = 665Ω (0.1%),

RSLOPE = 27k, fSW = 150kHz,

VCOMP = 2.52V, Measure

(Ton_lg2 - Ton_lg1)/(Ton_lg2 + Ton_lg1) *2

3

%

CURRENT SENSE AMPLIFIER

Minimum ISENxN and ISENxP

Common-Mode Voltage Range

Accuracy becomes worse when lower

than 4V

4

V

Maximum ISENxN and ISENxP

Common-Mode Voltage Range

55

V

Maximum Input Differential Voltage Range

VISENxP -

VISENxN

±0.3

V

ISENxP/ISENxN Bias Current

ISENxP/N_BIAS

Sourcing out of pin, EN = 5V,

VISENxN = VISENxP, VCM = 4V to 55V

100

123

150

µA

ZCD DETECTION - CSA

Zero Crossing Detection (ZCD) Threshold

VZCD_CSA

Measures voltage threshold before RSENat

CSA inputs (equivalent to the voltage

across the current sense shunt resistor),

RSET = 665Ω (0.1%)

-4.0

1.3

6.0

mV

PHASE DROPPING

VIMON Phase-Drop Falling Threshold, to Drop

Phase 2

VPHDRP_TH_F

When VIMON falls below VPHDRP_TH_F,

drop off Phase 2

1.0

1.1

1.2

V

VIMON Phase-Add Rising Threshold, to Add

Phase 2

VPHADD_TH_R

When VIMON rise above VPHADD_TH_R,

add back Phase 2

1.05

1.15

1.25

V

VIMON Phase-Drop Threshold Hysteresis

VPHDRP_HYS

When VIMON<VPHDRP_TH_F - VPHDrop_HYS,

add back Phase 2

45

50

55

mV

PEAK OVERCURRENT CYCLE-BY-CYCLE LIMITNG (OC1)

Peak Current Cycle-by-Cycle Limit Threshold

for Individual Phase

VOC1

Cycle-by-cycle current limit threshold

(IOC1_TH = 80µA, compared with ISENx).

Measures the voltage threshold before

RSETx at CSA Inputs (equivalent to the

voltage across the current sense shunt

resistor), RSETx = 665Ω (0.1%)

40

53

65

mV

Peak Current Cycle-by-Cycle Limit Trip Delay

CLG = OPEN, from the time VOC1 tripped to

LG falling

50

ns

PEAK OVERCURRENT FAULT PROTECTION OC2_PEAK, (Refer to “Peak Overcurrent Fault (OC2_PEAK) Protection” on page 35 for details)

Peak Current Fault Protection Threshold for

Individual Phase

VOC2

Peak current hiccup protection threshold

(IOC2_TH = 105µA, compared with ISENx).

Measures the voltage threshold before

RSETx at CSA Inputs (equivalent to the

voltage across the current sense shunt

resistor), RSETx = 665Ω (0.1%)

55

70

85

mV

OC2_PEAK Trip Blanking Time

3

cycles

Electrical Specifications Refer to Figure 3 on page 7 and Typical Application Schematics (page 8). Operating conditions unless

otherwise noted: VIN = 12V, VPVCC = 5.2V and VVCC = 5.2V, TA = -40°C to +125°C (Note 7). Typical values are at TA = +25°C. Boldface limits apply across

the operating temperature range, -40°C to +125°C. (Continued)

PARAMETER

SYMBOL

TEST CONDITIONS

MIN

(Note 6)

TYP

MAX

(Note 6) UNIT