LTC1142/LTC1142L/LTC1142HV
PI FU CTIO S
NDRIVE 1 (Pin 6):
High Current Drive for Bottom N-Channel
MOSFET, Section 1. Voltage swing at Pin 6 is from ground
to V
IN1
.
NC (Pins 7, 8):
No Connection.
PDRIVE 2 (Pin 9):
High Current Drive for Top P-Channel
MOSFET, Section 2. Voltage swing at this pin is from V
IN2
to ground.
V
IN2
(Pin 10):
Supply pin, section 2, must be closely
decoupled to section 2 power ground, Pin 19.
C
T2
(Pin 11):
External capacitor C
T2
from Pin 11 to ground
sets the operating frequency for the section 2. (The actual
frequency is also dependent upon the input voltage.)
INTV
CC2
(Pin 12) :
Internal supply voltage for section 2,
nominally 3.3V, can be decoupled to signal ground, Pin
18. Do not externally load this pin.
I
TH2
(Pin 13):
Gain Amplifier Decoupling Point, Section 2.
The section 2 current comparator threshold increases
with the Pin 13 voltage.
SENSE
–
2 (Pin 14):
Connects (–) input for the current
comparator on section 2.
SENSE
+
2 (Pin 15):
The (+) Input to the Section 2 Current
Comparator. A built-in offset between Pins 15 and 14 in
conjunction with R
SENSE2
sets the current trip threshold
for this section.
V
FB2
(Pin 16):
This pin serves as the feedback pin from an
external resistive divider used to set the output voltage for
section 2.
SHDN2 (Pin 17):
When grounded, the section 2 regulator
operates normally. Pulling Pin 17 high holds both MOSFETs
off and puts section 2 in micropower shutdown mode.
Requires CMOS logic signal with t
r
, t
f
< 1µs. Do not “float”
Pin 17.
SGND2 (Pin 18):
The section 2 small-signal ground must
be routed separately from other grounds to the (–) termi-
nal of the section 2 output capacitor.
PGND2 (Pin 19):
The section 2 driver power ground
connects to source of the N-channel MOSFET and the (–)
terminal of the section 2 input capacitor.
NDRIVE 2 (Pin 20):
High Current Drive for Bottom
N-Channel MOSFET, Section 2. Voltage swing at Pin 20 is
from ground to V
IN2
.
NC (Pins 21, 22):
No Connection.
PDRIVE 1 (Pin 23):
High Current Drive for Top P-Channel
MOSFET, Section 1. Voltage swing at this pin is from V
IN1
to ground.
V
IN1
(Pin 24):
Supply Pin, Section 1. Must be closely
decoupled to section 1 power ground Pin 5.
C
T1
(Pin 25):
External capacitor C
T1
from Pin 25 to ground
sets the operating frequency for section 1. (The actual
frequency is also dependent upon the input voltage.)
INTV
CC1
(Pin 26):
Internal supply voltage for section 1,
nominally 3.3V, can be decoupled to signal ground, Pin 4.
Do not externally load this pin.
I
TH1
(Pin 27):
Gain Amplifier Decoupling Point, Section 1.
The section 1 current comparator threshold increases
with the Pin 27 voltage.
SENSE
–
1 (Pin 28):
Connects to the (–) input for the
current comparator on section 1.
U
U
U
7
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