LTC1622CMS8 Linear Technology, LTC1622CMS8 Datasheet - Page 4

• Manufacturer Part Number: LTC1622CMS8
• Description: IC DC/DC CNTRLR STEP-DOWN 8-MSOP
• Manufacturer: Linear Technology
• Type: Step-Down (Buck)r

Specifications of LTC1622CMS8

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 0.8 ~ 9.8 V
• Current - Output: 1A
• Frequency - Switching: 110kHz ~ 550kHz
• Voltage - Input: 2 ~ 10 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -

LTC1622
PIN
SENSE
parator.
I
current comparator threshold increases with this control
voltage. Nominal voltage range for this pin is 0V to 1.2V.
V
nal resistive divider across the output capacitor.
RUN/SS (Pin 4): Combination of Soft-Start and Run
Control Inputs. A capacitor to ground at this pin sets the
ramp time to full output current. The time is approximately
0.45s/ F. Forcing this pin below 0.4V causes all circuitry
to be shut down.
4
TYPICAL PERFORMANCE CHARACTERISTICS
TH
FB
100
90
80
70
60
50
40
U
(Pin 3): Receives the feedback voltage from an exter-
(Pin 2): Error Amplifier Compensation Point. The
Efficiency vs Load Current for
Figure 1 with Burst Mode
Operation Defeated
1
FUNCTIONS
–
(Pin 1): The Negative Input to the Current Com-
U
V
IN
LOAD CURRENT (mA)
10
= 4.2V
V
IN
= 8.4V
U
100
V
R
V
OUT
SENSE
V
IN
IN
= 3.3V
= 6V
= 2.5V
W
= 0.03
1000
1622 G07
U
I
V
Load Step Transient Response
Burst Enabled
LOAD
IN
= 4.2V
= 50mA TO 1.2A
SYNC/MODE (Pin 5): This pin performs three functions.
Greater than 2V on this pin allows Burst Mode operation
at low load currents, while grounding or applying a clock
signal on this pin defeats Burst Mode operation. An
external clock between 625kHz and 750kHz applied to this
pin forces the LTC1622 to operate at the external clock
frequency. Do not attempt to synchronize below 625kHz .
Pin 5 has an internal 1 A pull-up current source.
GND (Pin 6): Ground Pin.
PDRV (PIN 7): Gate Drive for the External P-Channel
MOSFET. This pin swings from 0V to V
V
to ground Pin 6.
IN
(Pin 8): Main Supply Pin. Must be closely decoupled
1622 G08
Load Step Transient Response
Burst Inhibited
I
V
LOAD
IN
= 4.2V
= 50mA TO 1.2A
IN
.
1622 G09