Datasheet

LTC3829
8
3829fa
For more information www.linear.com/LTC3829
PIN FUNCTIONS
DIFFN (Pin 1/Pin 3): Negative Input of Remote Sensing
Differential Amplifier. Connect this to the remote load
ground pin.
DIFFP (Pin 2/Pin 4): Positive Input of Remote Sensing
Differential Amplifier. Must connect this to the remote load
positive terminal directly even when diffamp is not used.
RUN (Pin 3/Pin 5): Run Control Input. A voltage above
1.22V on this pin turns on the IC. There is a 1.0µA pull-up
current for this pin. Once the RUN pin rises above 1.22V,
an additional 4.5µA pull-up current is added to the pin.
AVP (Pin 4/Pin 6): Active Voltage Positioning Load Slope
Programming Pin. A resistor tied between this pin and the
DIFFP pin sets the load slope. The AVP function can only be
used with the remote sensing differential amplifier. Short
AVP pin and DIFFP pin when AVP is not used.
SENSE1
+
, SENSE2
+
, SENSE3
+
(Pins 5, 7, 11/Pins 7, 9,
13): Current Sense Comparator Inputs. The (+) inputs to
the current comparators are normally connected to DCR
sensing networks or current sensing resistors.
SENSE1
–
, SENSE2
–
, SENSE3
–
(Pins 6, 8, 12/Pins 8, 10,
14): Current Sense Comparator Inputs. The (–) inputs to
the current comparators are connected to the output.
(UHF/FE)
TYPICAL PERFORMANCE CHARACTERISTICS
Shutdown Current
vs Input Voltage
Shutdown Current vs Temperature
Quiescent Current vs Temperature
without EXTV
CC
INPUT VOLTAGE (V)
5 10
0
SHUTDOWN CURRENT (µA)
20
50
15
25
30
3829 G20
10
40
30
20
35
40
TEMPERATURE (°C)
–50
40
50
70
25 75
3829 G21
30
20
–25 0
50 100 125
10
0
60
SHUTDOWN CURRENT (µA)
TEMPERATURE (°C)
–50
QUIESCENT CURRENT (mA)
4
5
6
25 75
3829 G22
3
2
–25 0
50 100 125
1
0
TK/SS (Pin 9/Pin 11): Output Voltage Tracking and Soft-
Start Input. When one particular IC is configured to be the
master of two ICs, a capacitor to ground at this pin sets
the ramp rate for the master IC’s output voltage. When the
IC is configured to be the slave of two ICs, the V
FB
voltage
of the master IC is reproduced by a resistor divider and
applied to this pin. An internal soft-start current of 1.25µA
is charging this pin.
FREQ (Pin 10/Pin 12): There is a precision 10µA current
sourced out of this pin. A resistor to ground sets a voltage
which in turn programs the frequency. Alternatively, this
pin can be driven with a DC voltage to vary the frequency
of the internal oscillator.
V
FB
(Pin 13/Pin 15): Error Amplifier Feedback Input. This
pin receives the remotely sensed feedback voltage from
an external resistive divider.
I
TH
(Pin 14/Pin 16): Current Control Threshold and Error
Amplifier Compensation Point. Each associated channels’
current comparator tripping threshold increases with this
I
TH
control voltage.