Green-Mode PWM Controller
300mA Driving Capability
ST6850
DESCRIPTION
The ST6850 is the current mode PWM controller with green-mode power-saving
operation which can meet the low standby-power needs for low power SMPS. This green-
mode function enables the power supply to easily meet even the strictest power conservation
requirements. The small package provides the high efficiency / low cost solution for SMPS
power applications.
ST6850 is processed by BiCMOS fabrication, that enables reducing the start-up current
and the operating current. ST6850 is available by SOT-23-6L / DIP-8P packages.
PIN CONFIGURATION
SOT-23-6L
DIP-8P
APPLICATIONS
AC / DC Switching Power Adaptor
Battery Charger
PC 5V Standby Power
Open-Frame Switching Power Supply
FEATURE
High-Voltage BiCMOS Process
Very Low Startup Current( <25u )
Under Voltage Lockout( UVLO )
Current Mode Control
Current Limiting
Programmable Switching Frequency
Intermal Slope Compensation
Green-Mode Control for Power Saving
Non-audible-noise Green Mode Control
300mA Driving Capability
OVP (Over Voltage Protection) on Vcc
Pin
PART MARKING
SOT-23-6L
DIP-8P
ST6850
YYWW
STANSON TECHNOLOGY
120 Bentley Square, Mountain View, Ca 94040 USA
TEL: (650) 9389294 FAX: (650) 9389295
Page 1
Green-Mode PWM Controller
300mA Driving Capability
ST6850
TYPICAL APPLCTUON CIRCUIT ( High Efficiency SMPS )
ST6850
PIN DESCRIPTION
ST6850D8T
Pin
Symbol
1
OUT
2
VCC
3
NC
4
CS
5
6
7
RT
NC
COMP
Descripton
Gate driver output to drive the external MOSFET
Supply Voltage
Unconnected pin
Current sense. This pin senses the voltage across a resistor, to control PWM output. This
pin also provides current amplitude information for current-mode control.
This pin is used to charge an internal capacitor, to determine the switching frequency.
Unconnected pin
Voltage feedback. The pin provides the output voltage regulation signal. It provides
feedback to the internal PWM comparator, so that the PWM comparator can control the duty
cycle.
Grond
8
GND
STANSON TECHNOLOGY
120 Bentley Square, Mountain View, Ca 94040 USA
TEL: (650) 9389294 FAX: (650) 9389295
Page2
Green-Mode PWM Controller
300mA Driving Capability
ST6850
SP6850S26R
Pin
Symbol
Description
1
GND Ground
2
COMP Voltage feedback. The pin provides the output voltage regulation signal.. It provides
feedback to the internal PWM comparator, so that the PWM comparator can control the
duty cycle.
3
RT
This pin is used to charge an internal capacitor, to determine the switching frequency.
4
CS
Current sense. This pin senses the voltage across a resistor, to control PWM output. This
pin also provides current amplitude information for current-mode control.
6
VCC Supply Voltage
7
OUT Gate driver output to drive the external MOSFET
STANSON TECHNOLOGY
120 Bentley Square, Mountain View, Ca 94040 USA
TEL: (650) 9389294 FAX: (650) 9389295
Page3
Green-Mode PWM Controller
300mA Driving Capability
BLOCK DIAGRAM
ST6850
ORDERING INFORMATION
Part Number
ST6850D8TG
ST6850S26RG
※
ST6850D8T : Tube; Pb – Free
※
ST6850S26R: Tape Reel; Pb - Free
Package
DIP-8P
SOT-23-6L
Part Marking
ST6850
805YW
STANSON TECHNOLOGY
120 Bentley Square, Mountain View, Ca 94040 USA
TEL: (650) 9389294 FAX: (650) 9389295
Page 4
Green-Mode PWM Controller
300mA Driving Capability
ST6850
ABSOULTE MAXIMUN RATINGS
( Ta=25℃, unless otherwise specified.)
The following ratings designate persistent limits beyond which damage to the device may occur.
Symbol
Vcc
Ccomp/ Rt/ Cs
Pd
Pj
Tstg
Tlead
Parameter
DC Supply Vlotage
SYNC
Power Dissipation @ Ta=85℃*
Operating Junction Temperature Range
Storage Temperature Range
Lead Soldering Temperaature for 5 sec
Value
40
-3~7
0.3
150
150
Unit
V
V
W
℃
SOT-23-6L
220
℃
DIP-8P
260
SOT-23-6L
95
Thermal Resistance Junction-Case(*)
Rθjc
℃/W
DIP-8P
210
(*)The power dissipation and thermal resistance are evaluated under copper board mounted with free air
conditions.
STANSON TECHNOLOGY
120 Bentley Square, Mountain View, Ca 94040 USA
TEL: (650) 9389294 FAX: (650) 9389295
Page 5