long as the current limit value is reduced with re-

spect to the normal operating value. This is done

to limit voltage overshoots during core voltage

changes. Making this signal externally available

simplifies system debugging.

VID0-4(pin20-24): Voltage Identification code in-

put. These open collector compatible inputs are

used to program the output voltage as specified

in Table 1. Every pin has an internal pull up. If all

four pins are high or floating, the output voltage

and the 2.5V regulator are suspended and the

POWERGOOD is low.

NOSKIP(pin25): Pulse skipping mode control. A

high level (>2.4V) disables pulse skipping in low

load condition, a low level (>0.8V) enables it.

HSRC(pin26):

High

side

N-Channel

switch

source connection. This pin provides the return

path for the high side driver.

HGATE(pin27): Gate driver output, high side N-

Channel switch. The driver internal impedance is

about 4

Ω at VIN=12V.

HSTRAP(pin28):Bootstrap capacitor pin. This pin

provide to supply the high side driver sinking the

current by the bootstrap capacitor.

RSTRAP(pin29):

Synchronous rectifier

gate

driver supply voltage. This pin could be con-

nected to REG5 to reduce the switching losses

due to the external Mosfets gate capacitance.

This is useful to maintain an high efficiency at

light load.

RGATE(pin30): Gate driver output, low side N-

Channel switch. The driver internal impedance is

about 3

Ω at VIN=12V.

PWRGND(pin31): Power ground. This pin has to

be connected closely

to the low side mosfet

source in order to reduce the noise injected into

the IC.

POWER GOOD(pin32): Open drain power good

output. This pin is pulled low if the output voltage

is not within

±10% and the 2.5V output is lower

than 2.175V (-13%). The pin is pulled low also if

REG5, VPROG and VBG have not reached the

expected values. This test could be useful in an

assembling fault condition.

Table 1. VID [4:0] AND corresponding +VCC_CPU_CORE ranges

VID[4:0]

+VCC_CPU_CORE

VID[4:0]

+VCC_CPU_CORE

00000

2.00V

10000

1.275V

00001

1.95V

10001

1.250V

00010

1.90V

10010

1.225V

00011

1.85V

10011

1.200V

00100

1.80V

10100

1.175V

00101

1.75V

10101

1.150V

00110

1.70V

10110

1.125V

00111

1.65V

10111

1.100V

01000

1.60V

11000

1.075V

01001

1.55V

11001

1.050V

01010

1.50V

11010

1.025V

01011

1.45V

11011

1.000V

01100

1.40V

11100

0.975V

01101

1.35V

11101

0.950V

01110

1.30V

11110

0.925V

01111

No CPU

11111

No CPU

L5996

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