ISL78083

2. Specifications

R33DS0007EU0100 Rev.1.00

Page 13 of 33

Nov.15.19

2.7

LDO4 Electrical Specifications

VOUT3 Overvoltage Threshold

(Notes 9, 11)

VFB3(OV) VFB3 rising. Factory options: +4%, +6%, +12%

1.279

(+6.58%)

1.296

(+8%)

1.315

(+9.58%)

V

VFB3 falling hysteresis

-0.4%

-0.8%

-1.2%

%

Undervoltage Fault Delay

FB2 > VFB2 (UV), or FB3 > VFB3 (UV)

Factory option additional 10µs delay

2µs

Output Current Protection

Overcurrent Limit, Cycle-by-Cycle

(Note 12)

I2(LIM),

I3(LIM)

1.17

A

Overcurrent Hiccup Mode Delay

100

Cycles

Negative Current Limit

I2(NLIM),

I3(NLIM)

-0.99

-0.8

-0.60

A

Feedback Pin

FB2, FB3 Pin Input Impedance

RFB2,

RFB3

36

kΩ

Buck2 Soft-Start Ramp Time

VOUT2 = 1.8V

1.2

ms

Buck3 Soft-Start Ramp Time

VOUT3 = 1.2V

0.85

ms

Power MOSFETs

High-Side PMOS Switch

On-Resistance

IPHASE2,3 = 100mA, VIN2/3 = 3.8V

152

232

370

mΩ

Low-Side NMOS Switch

On-Resistance

IPHASE2,3 = 100mA, VIN2/3 = 3.8V

87

140

260

mΩ

PHASE2, PHASE3 Maximum Duty

Cycle

90

%

PHASE2, PHASE3 Minimum

On-Time

100

ns

TJ = -40°C to +150°C, VIN1 = 4V to 42V, unless otherwise noted. Typical values are at TJ = +50°C. Boldface limits apply across the

junction temperature range -40°C ≤ TJ ≤ +150°C.

Parameter

Symbol

Test Conditions

Min

Typ

Max

Unit

Input Supply

Input Voltage Range

VIN4

Connected to VOUT1, VIN2/3

3.3

5.5

V

Output Regulation

Output Voltage (Note 9)VLDOOUT4 Factory option 3.3V.

VIN2/3 = 3.8V, ILDOOUT4 = 100mA

3.260

(-1.21%)

3.29

3.332

(+0.96)

V

Dropout Voltage

ILDOOUT4 = 300mA, 2% drop at LDOOUT4

102

210

mV

Power Supply Rejection Ratio

At 1kHz, TA = 25°C,

“Typical Application Schematic” on page 4,

LDOIN4 = 3.8V, LDOOUT4 = 3.3V at 300mA

55

dB

LDOOUT4 Soft-Start Ramp Time

LDOOUT4 = 3.3V; CLDOOUT4 = 1µF

1.55

ms

Output Voltage Protection

Undervoltage Threshold

(Notes 9, 11)

VLDO4(UV) LDOOUT4 falling. Factory options: -4%, -6%, -12%

3.008

(-8.85%)

3.036

(-8%)

3.073

(-6.88%)

V

LDOOUT4 rising hysteresis

+0.4%

+0.8%

+1.2%

%

Overvoltage Threshold (Notes 9, 11)VLDO4(OV) LDOOUT4 rising. Factory options -4%, -6%, -12%

3.529

(+6.94%)

3.564

(+8%)

3.609

(+9.36%)

V

VLDOOUT4 falling hysteresis

-0.4%

-0.8%

-1.2%

%

TJ = -40°C to +150°C, VIN1 = 4V to 42V, unless otherwise noted. Typical values are at TJ = +50°C. Boldface limits apply across the

junction temperature range -40°C ≤ TJ ≤ +150°C. (Continued)

Parameter

Symbol

Test Conditions

Min

Typ

Max

Unit