High-Speed Step-Down Controller with

Accurate Current Limit for Notebook Computers

_______________________________________________________________________________________

3

ELECTRICAL CHARACTERISTICS (continued)

°C to +85°C, unless otherwise noted. Typical values are at

°C.)

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

REF Sink Current

REF in regulation

10

µA

REF Fault Lockout Voltage

Falling edge, hysteresis = 40mV

1.6

V

Overvoltage Trip Threshold

(Fixed-Threshold Mode)

With respect to error comparator threshold, no load

OVP = GND, rising edge, hysteresis = 1%

12

14.5

17

%

External feedback, measured at FB with respect to

-30

+30

mV

Overvoltage Comparator Offset

(Adjustable-Threshold Mode)

Internal feedback, measured at OUT with respect to the

rising edge, hysteresis = 1%

-3.5

+3.5

%

OVP Input Leakage Current

-100

0

+100

nA

Overvoltage Fault

Propagation Delay

FB forced 2% above trip threshold

1.5

µs

Output Undervoltage Protection

Trip Threshold (Fixed-Threshold

Mode)

65

70

75

%

External feedback, measured at FB with respect to

-40

+40

mV

Output Undervoltage Protection

Trip Threshold (Adjustable-

Threshold Mode)

Internal feedback, measured at OUT with respect to the

-5

+5

%

UVP Input Leakage Current

-100

<1

+100

nA

Output Undervoltage Protection

Blanking Time

From rising edge of SHDN

10

30

ms

PGOOD Trip Threshold (Lower)

With respect to error comparator threshold, no load

-12.5

-10

-8

%

PGOOD Trip Threshold (Upper)

With respect to error comparator threshold, no load

8

10

12.5

%

PGOOD Propagation Delay

FB forced 2% beyond PGOOD trip threshold, falling

10

µs

PGOOD Output Low Voltage

0.4

V

PGOOD Leakage Current

High state, forced to 5.5V

1

µA

ILIM Adjustment Range

0.25

3

V

Current-Limit Threshold (Fixed)

90

100

110

mV

40

50

60

Current-Limit Threshold

(Adjustable)

170

200

230

mV

Current-Limit Threshold

(Negative Direction)

-140

-117

-95

mV

Current-Limit Threshold

(Zero Crossing)

3

mV

Thermal Shutdown Threshold

Hysteresis = 10°C

150

°C

Lockout Threshold

Rising edge, hysteresis = 20mV,

PWM disabled below this level

4.1

4.4

V