SG6846BCSZ Fairchild Semiconductor, SG6846BCSZ Datasheet

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SG6846BCSZ

Manufacturer Part Number
SG6846BCSZ
Description
IC CTRLR PWM PROG OVP OTP 8SOP
Manufacturer
Fairchild Semiconductor
Datasheet

Specifications of SG6846BCSZ

Output Isolation
Isolated
Frequency Range
44.8 ~ 136kHz
Voltage - Input
10.5 ~ 30 V
Voltage - Output
18V
Power (watts)
400mW
Operating Temperature
-40°C ~ 150°C
Package / Case
8-SOIC (0.154", 3.90mm Width)
Number Of Outputs
1
Duty Cycle (max)
90 %
Mounting Style
SMD/SMT
Switching Frequency
136 KHz
Maximum Operating Temperature
+ 105 C
Fall Time
50 ns
Minimum Operating Temperature
- 40 C
Rise Time
350 ns
Synchronous Pin
No
Topology
Flyback
Lead Free Status / RoHS Status
Lead free / RoHS Compliant

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
SG6846BCSZ
Manufacturer:
FSC
Quantity:
7 600
Part Number:
SG6846BCSZ
Manufacturer:
FAIRCHILD/仙童
Quantity:
20 000
© 2008 Fairchild Semiconductor Corporation
SG6846B • Rev. 1.3.4
SG6846B
Highly Integrated Green-Mode PWM Controller
Features
Applications
General-purpose switch-mode power supplies and
flyback power converters, including:
Ordering Information
SG6846BLSY
SG6846BLSZ
SG6846BCSY
SG6846BCSZ
Number
For Fairchild’s definition of “green” Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.
Low Startup Current: 8µA
Low Operating Current: 3.7mA
Peak-Current Mode Operation with Cycle-by-cycle
Current Limiting
PWM Frequency Continuously Decreasing with
Burst Mode at Light Loads
V
AC Input Brownout Protection with Hysteresis
Constant Output Power Limit (Full AC Input Range)
Internal Latch Circuit for OVP, OTP, and OCP
(BLSY, BLSZ)
Two-level OCP Delay with 200ms
Programmable PWM Frequency with Frequency
Hopping
OCP Threshold is 2/3 Peak Current Limit
Soft Startup Time: 5ms
Power Adapters
Open-frame SMPS
SMPS with Surge-current Output, such as for
Printers, Scanners, Motor Drivers
Part
DD
Over Voltage Protection (OVP)
Temperature Range
-40 to +105°C
-40 to +105°C
-40 to +105°C
-40 to +105°C
Operating
Latch
OCP
Yes
Yes
No
No
Status
Green
Green
RoHS
RoHS
Eco
Description
The highly integrated PWM controller, SG6846B,
provides several features to enhance the performance
of fly-back converters. To minimize standby power
consumption,
provides off-time modulation to continuously decrease
the switching frequency under light-load conditions.
Under zero-load conditions, the power supply enters
burst-mode. This completely shuts off PWM output. If
V
green-mode function enables power supplies to meet
international power conservation requirements.
The SG6846B is designed for SMPS with surge-current
output. It is incorporated with a two-level OCP function.
Besides, the cycle-by-cycle current limiting, if the
switching current is higher than OCP threshold and
lasts for 200ms, SG6846B stops gate immediately and
latches itself (BLSY version) or restarts after V
charges up to 16.5V (BCSY version). SG6846B also
integrates frequency-hopping function internally. The
frequency hopping function helps reduce EMI emission
of a power supply with minimum line filters. It has built-
in
internal compensation for constant output power limit
over universal AC input range. The gate output is
clamped at 18V to protect the external MOSFET from
over-voltage damage.
Protection include: AC input brownout protection with
hysteresis and V
temperature protection, an external NTC thermistor can
be applied to sense the ambient temperature. When
OCP, V
circuit is used to latch-off the controller. The latch resets
when V
SG6846B is available in 8-pin SOP package.
FB
is larger than around 1.6V, PWM pulses out. This
synchronized
8-Pin Small Outline Package (SOP)
8-Pin Small Outline Package (SOP)
8-Pin Small Outline Package (SOP)
8-Pin Small Outline Package (SOP)
DD
DD
supply is removed.
OVP, or OTP are activated, an internal latch
a
Package
DD
proprietary
slope
over-voltage protection. For over-
compensation,
green-mode
October 2008
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel
www.fairchildsemi.com
Packing
Method
proprietary
function
DD

Related parts for SG6846BCSZ

SG6846BCSZ Summary of contents

Page 1

... SG6846BLSY -40 to +105°C SG6846BLSZ -40 to +105°C SG6846BCSY -40 to +105°C SG6846BCSZ -40 to +105°C For Fairchild’s definition of “green” Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html. © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 Description The highly integrated PWM controller, SG6846B, provides several features to enhance the performance of fly-back converters ...

Page 2

... Typical Application L EMI AC input Filter N VIN Block Diagram 0.9V/0.7V VIN 3 V -TH-G DD VDD 7 UVLO 16.5V/10.5V 23. 1.05V © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3 VDD GATE 8 SENSE 6 GND SG6846B Figure 1. Typical Application Over Power Compersation 0.895-0.065 Internal BIAS Latch Debounce ...

Page 3

... Marking Information SG6846BFTP XXXXXXXXYWWV ※ Marking for SG6846BLSZ (Pb-free) SG6846BCSZ (Pb-free) ※ Marking for SG6846BLSY (Green-compound) SG6846BCSY (Green-compound) © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3 OCP Latch OCP auto-recovery SOP Lead Free + ROHS Compatible Null = regular package XXXXXXXX: Wafer Lot Y: Year ...

Page 4

... VDD Power Supply 8 GATE Driver Output © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 Figure 5. Pin Configuration Description Ground. The signal from the external compensation circuit is fed into this pin. The PWM duty cycle is determined in response to the signal from this pin and the current- sense signal from pin 6 ...

Page 5

... The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to Absolute Maximum Ratings. Symbol T Operating Ambient Temperature A © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 Parameter <50°C SOP A SOP ...

Page 6

... Delay Time for Over-Current Protection D-OCP t Output Short Circuit Protection delay time D-Short t SS-65KHz Period During Soft Start Time t SS-130KHz © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 Test Condition for Short-Circuit DD V – 0.16V DD-ON GATE Open R = 26kΩ ...

Page 7

... FB-N Reduction Threshold Jitter Range V FB Voltage at f FB-G OSC-G f Frequency Variation vs Frequency Variation vs. Temperature f DT Deviation © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3 Timing = 200ms OCP Figure 6. SG6846B OCP/SCP Logic Flow Diagram (Continued) Test Condition Center Frequency R = 26kΩ, V ...

Page 8

... The relationship between R © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 (Continued) Test Condition V = 15V 12V GATE = 1nF GATE = 1nF V = 20V DD ( 26kΩ I SG6846BLSY or SG6846BCSY 26kΩ SG6846BLSZ or SG6846BCSZ 26kΩ ( 26kΩ and R is: RT-OFF OFF OTP - LATCH 8 Min. Typ. Max. 80 ...

Page 9

... Temperature ( ℃ ) Figure 9. Startup Current (I OCP Threshold Voltage for Current Limit (V Temperature -40 -25 - Temperature (℃ ) Figure 11. OCP Threshold Voltage for Current Limit (V ) vs. Temperature STH1V-2/3 © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3 Temperature DD- Figure 8. Turn-off Threshold Voltage (V DD- Temperature ...

Page 10

... Figure 15. Output Current of RT pin (I vs. Temperature PW M Turn-on Threshold Voltage (V 0.925 0.920 0.915 0.910 0.905 -40 -25 - Temperature ( ℃ ) Figure 17. PWM Turn-on Threshold Voltage (V vs. Temperature © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 (Continued Temperature OSC 8 7.2 8 7.0 8 6.8 8 6.6 8 6 110 125 ...

Page 11

... PWM frequency. Using a 26kΩ resistor results in a corresponding 65kHz switching frequency. The relationship between R frequency is: © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 f (kHz) PWM If an open-circuit or short-circuit to ground occurs at the RI pin, the internal protection circuit immediately shuts down the controller ...

Page 12

... Good placement and layout practices should be followed. Avoid long PCB traces and component leads. Compensation and filter components should be located near the SG6846B. © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 (Continued) Slope compensation 12 Figure 19 ...

Page 13

... R7 27KΩ +/-5% R6 330Ω +/-1% R19 102KΩ +/-1% R14 0Ω22 +/-5% R16, R17 1W 20Ω +/-5% R11 20KΩ +/-5% R12 100KΩ +/-5% R20 887KΩ +/-1% R22 10KΩ +/-1% © 2008 Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 BD1 LF2 CX2 R12 ...

Page 14

... Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products. Always visit Fairchild Semiconductor’ ...

Page 15

... Fairchild Semiconductor Corporation SG6846B • Rev. 1.3.4 15 www.fairchildsemi.com ...

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