LTC3857IUH#TRPBF Linear Technology, LTC3857IUH#TRPBF Datasheet - Page 9

• Manufacturer Part Number: LTC3857IUH#TRPBF
• Description: IC CTRLR STP-DN SYNC DUAL 32QFN
• Manufacturer: Linear Technology
• Series: PolyPhase®r
• Type: Step-Down (Buck)r

Specifications of LTC3857IUH#TRPBF

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 2
• Voltage - Output: 0.8 ~ 24 V
• Frequency - Switching: 50kHz ~ 900kHz
• Voltage - Input: 4 ~ 38 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 32-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Power - Output: -

TG1, TG2 (Pin 26, Pin 15): High Current Gate Drives for
Top N-Channel MOSFETs. These are the outputs of float-
ing drivers with a voltage swing equal to INTV
superimposed on the switch node voltage SW.
PGOOD1, PGOOD2 (Pin 27, Pin 14): Open-Drain Logic
Output. PGOOD1,2 is pulled to ground when the voltage
on the V
I
Inputs. Tying this pin to SGND, FLOAT or INTV
maximum current sense threshold to one of three different
levels for both comparators.
TRACK/SS1, TRACK/SS2 (Pin 29, Pin 13): External
Tracking and Soft-Start Input. The LTC3857 regulates the
V
TRACK/SS1,2 pin. An internal 1μA pull-up current source
is connected to this pin. A capacitor to ground at this
pin sets the ramp time to final regulated output voltage.
Alternatively, a resistor divider on another voltage supply
connected to this pin allows the LTC3857 output to track
the other supply during start-up.
PIN FUNCTIONS
LIM
FB1,2
(Pin 28): Current Comparator Sense Voltage Range
voltage to the smaller of 0.8V or the voltage on the
FB1,2
pin is not within ±10% of its set point.
CC
CC
sets the
– 0.5V
I
Switching Regulator Compensation Points. Each associ-
ated channel’s current comparator trip point increases
with this control voltage.
V
feedback voltage for each controller from an external
resistive divider across the output.
SENSE1
differential current comparators are normally connected
to DCR sensing networks or current sensing resistors.
The I
SENSE
the current trip threshold.
TH1
FB1
, I
, V
TH
TH2
–
FB2
+
pin voltage and controlled offsets between the
and SENSE
, SENSE2
(Pin 30, Pin 12): Error Amplifier Outputs and
(Pin 31, Pin 11): Receives the remotely sensed
+
+
(Pin 32, Pin 10): The (+) input to the
pins in conjunction with R
LTC3857
SENSE
3857fc
9
set