TC120
PWM/PFM Step-Down Combination Regulator/Controller
Features
鈥?Internal Switching Transistor Supports 600mA
Output Current
鈥?External Switching Transistor Control for Output
Currents of 2A+
鈥?300kHz Oscillator Frequency Supports Small
Inductor Size
鈥?Short Circuit Protection
鈥?Built-In Undervoltage Lockout
鈥?95% Typical Efficiency
鈥?Automatic Switchover to Current-Saving PFM
Mode at Low Output Loads
鈥?Automatic Output Capacitor Discharge While in
Shutdown
鈥?Programmable Soft-Start
鈥?Power-Saving Shutdown Mode
鈥?Small 8-Pin SOP Package
Package Type
8-Pin SOP
V
IN
1
EXTW 2
CPC 3
SHDN/SS 4
8
L
X
EXT
GND
SENSE
TC120
7
6
5
General Description
TC120 is a 300kHz PFM/PWM step-down (Buck) DC/
DC regulator/controller combination for use in systems
operating from two or more cells, or in line-powered
applications. It uses PWM as the primary modulation
scheme, but automatically converts to PFM at low
output loads for greater efficiency. It requires only an
external inductor, Schottky diode, and two capacitors to
implement a step-down converter having a maximum
output current of 600mA (V
IN
= 5V, V
OUT
= 3.3V). An
external switching transistor (P-channel MOSFET) can
be added to increase output current capability to
support output loads of 2A or more.
The TC120 consumes only 55碌A(chǔ) (max) of supply
current (V
OUT
= 3.3V) and can be placed in shutdown
mode by bringing the shutdown input (SHDN) low.
During shutdown, the regulator is disabled, supply
current is reduced to 2.5碌A(chǔ) (max), and V
OUT
is
internally pulled to ground, discharging the output
capacitor. Normal operation resumes when SHDN is
brought high. Other features include a built-in under-
voltage lockout (UVLO), an externally programmable
soft start time, and output short circuit protection. The
TC120 operates from a maximum input voltage of 10V
and is available in a low-profile 8-Pin SOP package.
Applications
鈥?/div>
鈥?/div>
鈥?/div>
鈥?/div>
鈥?/div>
鈥?/div>
Portable Test Equipment
Local Logic Supplies
Portable Audio Systems
Portable Scanners
Palmtops
Electronic Organizers
Device Selection Table
Part
Number
TC120503EHA
TC120333EHA
TC120303EHA
Output
Voltage
(V)
5.0
3.3
3.0
Package
Operating
Temp.
Range
8-Pin SOP -40擄C to +85擄C
8-Pin SOP -40擄C to +85擄C
8-Pin SOP -40擄C to +85擄C
Functional Block Diagram
V
IN
V
IN
C
IN
EXTW
EXT
L
X
D1
C
OUT
L1
V
OUT
TC120XX03
CPC
GND
SHDN/SS
C
SS
4.7nF
SENSE
2002 Microchip Technology Inc.
DS21365B-page 1
漏
TC120503EHA相關(guān)型號(hào)PDF文件下載
-
型號(hào)
版本
描述
廠商
下載
-
英文版
LOW COST, ONE WIRE DIGITAL THERMOMETER WITH SHUTDOWN
TELCOM
-
英文版
LOW COST, ONE WIRE DIGITAL THERMOMETER WITH SHUTDOWN
TELCOM [Te...
-
英文版
PWM/PFM Step-Down Combination Regulator/Controller
-
英文版
PWM/PFM Step-Down Combination Regulator/Controller
MICROCHIP ...
-
英文版
PFM Step-Up DC/DC Regulators
-
英文版
PFM Step-Up DC/DC Regulators
MICROCHIP ...
-
英文版
PFM Step-Up DC/DC Regulators
-
英文版
PFM Step-Up DC/DC Regulators
MICROCHIP ...
-
英文版
Super Low Noise GaAs FETs
ETC [ETC]
-
英文版
Switched Capacitor Voltage Converters with Shutdown in SOT P...
MICROCHIP ...
-
英文版
Switched Capacitor Voltage Converters with Shutdown in SOT P...
-
英文版
Switched Capacitor Voltage Converters with Shutdown in SOT P...
MICROCHIP ...
-
英文版
High Frequency Switched Capacitor Voltage Converters with Sh...
-
英文版
High Frequency Switched Capacitor Voltage Converters with Sh...
MICROCHIP ...
-
英文版
High Frequency Switched Capacitor Voltage Converters with Sh...
-
英文版
High Frequency Switched Capacitor Voltage Converters with Sh...
MICROCHIP ...
-
英文版
50mA and 100mA CMOS LDOs with Shutdown
-
英文版
50mA and 100mA CMOS LDOs with Shutdown
-
英文版
Inverting Dual (-VIN, -2VIN) Charge Pump Voltage Converters
-
英文版
Inverting Dual (-VIN, -2VIN) Charge Pump Voltage Converters
MICROCHIP ...
MICROCHIP
1
2
3
4
5
6
7
8
9
10
11
12
13
14
