ltc4215-1 Linear Technology Corporation, ltc4215-1 Datasheet - Page 9

• Manufacturer Part Number: ltc4215-1
• Description: Hot Swap Controller With Adc And I2c Compatible Monitoring
• Manufacturer: Linear Technology Corporation

PIN FUNCTIONS
FUNCTIONAL DIAGRAM
MOSFET switch for gate drive return. This pin also serves as
the ADC input to monitor output voltage. The pin provides
a return for the gate pull-down circuit.
SS: Sets the inrush current slew rate at start-up. Connect
a 68nF capacitor to provide 5mV/ms as the slew rate for
the sense voltage in start-up. This corresponds to 1A/ms
with a 5mΩ sense resistor. Note that a large soft-start
capacitor and a small TIMER capacitor may result in a
condition where the timer expires before the inrush current
has started. Allow an additional 10nF of timer capacitance
per 1nF of soft-start capacitor to ensure proper start-up.
Use 1nF minimum to ensure an accurate inrush current.
TIMER: Start-Up Timer Input. Connect a capacitor be-
tween this pin and ground to set a 12.3ms/μF duration
for start-up, after which an overcurrent fault is logged if
the inrush is still current limited. The duration of the off
SS
FB
UV
OV
EN
ON
V
ADIN
SDAI
SDAO
SCL
ALERT
DD
INTV
CC
10μA
1.235V
1.235V
1.235V
1.235V
2.84V
15.6V
0.4V
10μA
+
–
+
–
+
–
+
–
+
–
+
–
+
–
V
CC
UVLO1
I
2
RST
OV1
OV2
UV
ON
EN
C
V
RESET
OV
DD(UVLO)
OV2
UV
EN
ON
1.235V
0.6V
1.235V
FOLDBACK
AND dI/dt
+
–
V
DD
PG
– V
SOURCE
PWRGD
SENSE
FAULT
I
TM1
TM2
2
C ADDR
CB
LOGIC
SENSE
time is 600ms/μF when overcurrent auto retry is enabled,
resulting in a 1:50 duty cycle. An internal timer provides
a 100ms start-up time and 5 seconds auto-retry time if
this pin is tied to INTV
timer capacitance per 1nF of soft-start (SS) capacitor to
ensure proper start-up. The minimum value for the TIMER
capacitor is 10nF .
UV: Undervoltage Comparator Input. Connect this pin
to an external resistive divider from V
at this pin falls below 1.227V, an undervoltage fault is
detected and the GATE turns off. Pulling this pin below
0.4V resets all faults and allows the GATE to turn back on.
Tie to INTV
V
lockout threshold of 2.84V and overvoltage lockout
threshold of 15.6V
+
–
+
–
+
–
DD
–
5
0.2V
1.235V
–
: Supply Voltage Input. This pin has an undervoltage
+
CONVERTER
1 OF 9
+ –
SENSE
A/D
CC
+
–
+
UVLO2
100μA
2μA
8
if unused.
CS
GP
GP
GP
+
–
+
–
+
–
+
–
FET ON
GATE DRIVER
1.6V
1.6V
1V
2.64V
PUMP AND
CHARGE
3.1V
GEN
CC
. Allow an additional 10nF of
SOURCE
INTV
TIMER
GPI03
GPI02
GPI01
ADRO
ADR1
GATE
CC
4215 BD
LTC4215-1
DD
. If the voltage
42151f
9