UC3845A Datasheet PDF - ETC
Part Number | UC3845A | |
Description | High Performance Current Mode PWM Controller | |
Manufacturers | ETC | |
Logo | ||
There is a preview and UC3845A download ( pdf file ) link at the bottom of this page. Total 8 Pages |
Preview 1 page No Preview Available ! Replacement of
UC3842A/43A/44A/45A
High Performance Current
Mode PWM Controller
MIK3842A/43A/44A/45A
July 1995 –revised July 2002
Description
The MIK3842A(AM)/43A(AM)/44A(AM)/45A(AM) are fixed frequency current mode PWM controller. They are specially designed for
OFF−Line and DC to DC converter applications with a minimal external components. Internally implemented circuits include a trimmed
oscillator for precise duty cycle control, a temperature compensated reference, high gain error amplifier, current sensing comparator,
and a high current totempole output ideally suited for driving a power MOSFET. Protection circuitry includes built undervoltage lockout
and current limiting. The MIK3842A(AM) and MIK3844A(AM) have UVLO thresholds of 16 V (on) and 10 V (off). The corresponding
thresholds for the MIK3843A(AM)/45A(AM) are 8.4V (on) and 7.6V (off). The MIK3842A(AM) and MIK3843A(AM) can operate within 100%
duty cycle. The MIK3844A(AM) and UC3845A(AM) can operate within 50% duty cycle.
The MIK384XA(AM) has Start-Up Current 0.17mA (typ).
Features
• Low Start-Up and Operating Current
• High Current Totem Pole Output
• Undervoltage Lockout With Hysteresis
• Operating Frequency Up To 300KHz (MIK384XA)
500KHz (MIK384XAM)
Pin Connection
VREF
8
Block diagram
(toggle flip flop used only in MIK3844, MIK3845)
5V
VREF
SET/
RESET
UVLO
Top view
VCC 7
36V GND
5
INTERNAL
BIAS
VREF GOOD
LOGIC
2 VFB
1/2 VREF
+ ERR
- AMP
COMP
1
CURRENT
SENSE
3
2R
R
C.S.
COMP
1V
4 RT/CT
OSCILLATOR
R
PWM
LATCH
S
T
POWER VCC
7
OUT
6
5
POWER GND
Absolute Maximum Ratings
Symbol
Parameter
VCC
IO
VI
ISINK (E.A)
PO
Tstg
TL
Supply Voltage (low impedance source)
Output Current
Input Voltage (Analog Inputs pins 2,3)
Error Amp Output Sink Current
Power Dissipation (TA=250C)
Storage Temperature Range
Lead Temperature (soldering 5 sec.)
Maximum
30
±1
−0.3 to 5.5
10
1
-65 to150
260
Units
V
A
V
mA
W
oC
oC
Page 1 of 8
|
|
Replacement of
UC3842A/43A/44A/45A
MIK3842A/43A/44A/45A
High Performance Current
Mode PWM Controller
July 1995 –revised July 2002
Figure 7. External Clock Synchronization
Figure 8. Soft-Start Circuit
Page 5 of 8
Preview 5 Page |
Part DetailsOn this page, you can learn information such as the schematic, equivalent, pinout, replacement, circuit, and manual for UC3845A electronic component. |
Information | Total 8 Pages | |
Link URL | [ Copy URL to Clipboard ] | |
Download | [ UC3845A.PDF Datasheet ] |
Share Link :
Electronic Components Distributor
An electronic components distributor is a company that sources, stocks, and sells electronic components to manufacturers, engineers, and hobbyists. |
SparkFun Electronics | Allied Electronics | DigiKey Electronics | Arrow Electronics |
Mouser Electronics | Adafruit | Newark | Chip One Stop |
Featured Datasheets
Part Number | Description | MFRS |
UC3845 | The function is Current Mode PWM Controller (Rev. C). Texas Instruments | |
UC3845 | The function is (UC3842 - UC3845) SMPS Controller. Fairchild Semiconductor | |
UC3845 | The function is (UC3842 - UC3845) CURRENTMODE PWM CONTROLLER. ST Microelectronics | |
Semiconductors commonly used in industry:
1N4148 |  
BAW56 |
1N5400 |
NE555 | | ||
Quick jump to:
UC38
1N4
2N2
2SA
2SC
74H
BC
HCF
IRF
KA |