ISL6173_14 Datasheet, PDF (4/20 Pages) Intersil Corporation – Dual Low Voltage Hot Swap Controller

ISL6173
Pin Descriptions (Continued)
PIN NAME
FUNCTION
DESCRIPTION
11
CPQ- Charge Pump Capacitor Flying cap lowside.
Low Side
12
BIAS Chip Bias Voltage
Provides IC Bias. Should be 2V to 4V for IC to function normally. This pin can be powered from a
supply voltage that is not being controlled. It is preferable to use 3.3V even if the channels being
controlled are 2.5V or lower because more gate drive voltage will be available to the MOSFETs.
13
CPQ+ Charge Pump Capacitor Flying cap highside. Use of 0.1µF for 2.5V bias and 0.022µF for 3.3V bias is recommended.
High Side
14 CPVDD Charge Pump Output This is the voltage used for some internal pullups and bias. Use of 0.47µF (minimum) is
recommended.
15
CT2 Timer Capacitor
Same function as pin 7
16
PG2 Power Good Output Same function as pin 6
17
FLT2 Fault Output
Same as pin 5
18
GT2 Gate Drive Output
Same as pin 4
19
SS2 Soft-Start Duration Set Same as pin 3
Input
20
VO2 Output Voltage 2
Same as pin 2
21
SNS2 Current Sense Input Same as pin 1
22
VS2 Current Sense
Reference
Voltage input for one of the two voltages. Provides a 20µA current source for the ISET series resistor
which sets the voltage to which the sense resistor IR drop is compared.
23
UV2 Undervoltage Monitor This pin is one of the two inputs to the undervoltage comparator. The other input is the 633mV
Input
reference. It is meant to sense the output voltage through a resistor divider. If the output voltage
drops so that the voltage on the UV pin goes below 633mV, PG2 is deasserted.
24
EN2 Enable
This is an active low input. When asserted (pulled low), the SS and gate drive are released and the
output voltage gets enabled. When deasserted (pulled high or left floating), the reverse happens.
25 OCREF Ref. Current Adj.
Allows adjustment of the reference current through R_SET and the internal current regulation set
resistor, thus setting the thresholds for CR, OC and WOC.
26
EN1 Enable Input
Same as pin 24
27
UV1 Undervoltage Monitor Same as pin 23
Input
28
VS1 Current Sense
Reference
Same as pin 22
4
FN9186.3
January 3, 2006