lt8410-1 Linear Technology Corporation, lt8410-1 Datasheet - Page 7

• Manufacturer Part Number: lt8410-1
• Description: Ultralow Power Boost Converter With Output Disconnect
• Manufacturer: Linear Technology Corporation

PIN FUNCTIONS
SHDN (Pin 1): Shutdown Pin. This pin is used to enable/
disable the chip. Drive below 0.3V to disable the chip. Drive
above 1.4V to activate the chip. Do not fl oat this pin.
V
to GND. See typical applications section.
GND (Pin 3 and Pin 9): Ground. Tie directly to local ground
plane. Pin 9 is fl oating but must be grounded for proper
shielding.
SW (Pin 4): Switch Pin. This is the collector of the
internal NPN power switch. Minimize the metal trace area
connected to this pin to minimize EMI.
V
a bypass capacitor from this pin to GND.
CAP (Pin 6): This is the cathode of the internal Schottky
Diode. Place a bypass capacitor from this pin to GND.
BLOCK DIAGRAM
CC
OUT
(Pin 2): Input Supply Pin. Must be locally bypassed
(Pin 5): Drain of Output Disconnect PMOS. Place
V
FBP
REF
7
8
V
2
CC
MAX
10μA
DISCHARGE
CONTROL
+
–
1.235V
1.235V
ENABLE
CHIP
FB
–
+
+
+
–
V
by placing a capacitor from this pin to GND. This cap
will be discharged for 70μs (typical) at the beginning
of start-up and then be charged to 1.235V with a 10μA
current source.
FBP(Pin 8): Positive Feedback Pin. This pin is the error
amplifi er’s positive input terminal. To achieve the desired
output voltage, choose the FBP pin voltage (V
to the following formula:
V
For protection purposes, the output voltage can not exceed
40V even if V
REF
FBP
1.235V
= V
(Pin 7): Reference Pin. Soft-start can be achieved
SHDN
VC
1
OUT
CURRENT CONTROL
TIMING AND PEAK
/ 31.85
FBP
GND
12.4M
9
400K
is driven higher than V
V
OUT
LT8410/LT8410-1
5
OUTPUT DISCONNECT
CONTROL
CONTROL
SWITCH
CAP
6
+
–
REF
FBP
.
) according
GND
SW
4
3
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