lt1106cf Linear Technology Corporation, lt1106cf Datasheet - Page 5

• Manufacturer Part Number: lt1106cf
• Description: Micropower Step-up Dc/dc Converter For Pcmcia Card Flash Memory
• Manufacturer: Linear Technology Corporation

PI FU CTIO S
SELECT 12/5 (Pin 1): Tie to V
tie to GND or logic 0 for 12V output.
SOFT START (Pin 2): A 0.1 F/1M parallel RC from this
pin to GND provides a Soft Start function upon device
turn-on. Initially about 80 A will flow from the pin into the
capacitor. When the voltage at the pin reaches approxi-
mately 0.4V, current ceases flowing out of the pin. See
Applications Information section.
V
together. At least 1 F input bypass capacitance is re-
quired. More capacitance reduces ringing on the supply
line.
3/5 (Pin 5): Supply Comparator Output. This pin provides
logic output indicating the value of the input supply. High
when V
PGND (Pins 6, 7): Power Ground. Connect to ground plane.
V
dt present on this pin. To minimize radiated noise keep
layout short and direct.
GND (Pin 13): Signal Ground. Connect of ground plane.
VPP VALID (Pin 14): This pin provides a logic signal
indicating that ouput voltage is greater than 11.4V. Active
low with internal 200k pull-up resistor.
CC
SW
U
(Pins 3, 4): Input Supply. Both pins should be tied
(Pins 9, 10, 11): Collector of Power Switch. High dV/
CC
= 5V; low when V
U
U
CC
IN
= 3.3V.
or logic 1 for 5V output;
G1, G2 (Pins 16, 15): External MOSFET Gate Drives. When
VPP1 or VPP2 is greater than 11.7V, G1 or G2 is driven to
about 0.8V. When VPP1 or VPP2 is less than 11.7V, the
drives assume a high impedance state pulled up to the
AVPP pin through an internal 100k resistor.
VPP1, VPP2 (Pins 18, 17): Programming Power Inputs.
The LT1106 senses both VPP1 and VPP2 supplies at the
PCMCIA card socket. If VPP1 or VPP2 is greater than 11V,
the LT1106 operates in “Doze” Mode — the switching
regulator turns off and the drive to external P-channel
MOSFETs turns on. Supply current in Doze Mode is about
350 A. Input current into VPP1 and VPP2 is about 1 A
when the device is shut down.
AVPP (Pin 19): Output Sense Pin. This pin connects to a
1M
shutdown, the resistor string is disconnected and current
into this pin is reduced to < 1 A.
ON/OFF (Pin 20): Shutdown Control. When pulled below
1.5V, this pin disables the LT1106 and reduces supply
current to 10 A. All circuitry except the 3/5 comparator
is disabled in shutdown. The part is enabled when
ON/OFF is greater than 1.5V.
resistive divider that sets the output voltage. In
LT1106
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