Quick-PWM Step-Down Controllers with Inductor

Saturation Protection and Dynamic Output Voltages

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7

ELECTRICAL CHARACTERISTICS (continued)

PARAMETER

SYMBOL

CONDITIONS

MIN

MAX

UNITS

INPUTS AND OUTPUTS

Logic Input Threshold

SHDN, SKIP, GATE

rising edge, hysteresis = 225mV

1.20

2.20

V

High

1.9

2.1

Dual Mode Threshold Voltage

MAX1992 FB

Low

0.05

0.15

V

High

0.4V

Open

3.15

3.85

REF

1.65

2.35

Four-Level Input Logic Levels

TON, OVP/UVP,

LSAT, FBLANK

Low

0.5

V

Note 2: When the inductor is in continuous conduction, the output voltage has a DC regulation level higher than the error compara-

tor threshold by 50% of the output ripple. In discontinuous conduction (

SKIP = GND, light load), the output voltage has a

DC regulation level higher than the trip level by approximately 1.5% due to slope compensation.

and a 250pF capacitor connected from DH to LX. Actual in-circuit times can differ due to MOSFET switching speeds.

Note 4: Specifications to -40°C are guaranteed by design, not production tested.

Typical Operating Characteristics

unless otherwise noted.)

EFFICIENCY vs. LOAD CURRENT

LOAD CURRENT (A)

1

0.1

60

70

80

90

100

50

0.01

10

SKIP = GND

2.5V OUTPUT VOLTAGE

vs. LOAD CURRENT

LOAD CURRENT (A)

4

3

1

2

2.48

2.49

2.50

2.51

2.52

2.53

2.54

2.55

2.47

05

SKIP = GND

EFFICIENCY vs. LOAD CURRENT

LOAD CURRENT (A)

1

0.1

60

70

80

90

100

50

0.01

10

SKIP = GND