Catalog
UC3842AN Description
The UCx84xA family of control devices is a pin-for-pin compatible improved version of the UCx84x family. Providing the necessary features to control currentmode or switched-mode power supplies, this family of devices has many improved features: startup current is less than 0.5 mA, oscillator discharge is trimmed to 8.3 mA, and during UVLO, the output stage can sink at least 10 mA at less than 1.2 V for VCC over 5 V.
Video: Current Mode PWM SMPS controller UC3842
UC3842 Video Description:
in this video i discussed Functional Description of Current Mode PWM SMPS controller UC3842
Video: UC3842 OPEN LOOP TEST CIRCUIT (Alfaro, Bugnot, Maramara, Ocampo, Pascual)
UC3842AN Video Description:
The UC3842 is a fixed frequency current-mode PWM controller. They are specially designed for Off-Line and DC to DC converter applications with minimum external components. These integrated circuits feature a trimmed oscillator for precise duty cycle control, a temperature compensated reference, high gain error amplifier, current sensing comparator and a high current totem pole output for driving a Power MOSFET.
UC3842AN CAD Models
Figure: UC3842AN Part Symbol
Figure: UC3842AN Footprint
Figure: UC3842AN 3D Model
UC3842AN Pin Configurations
Figure: UC3842AN Pin Configurations
UC3842AN Features
- Optimized for Off-Line and DC-DC Converters
- Low Start-Up Current (< 0.5 mA)
- Trimmed Oscillator Discharge Current
- Automatic Feedforward Compensation
- Pulse-by-Pulse Current Limiting
- Enhanced Load Response Characteristics
- Undervoltage Lockout With Hysteresis
- Double Pulse Suppression
- High-Current Totem Pole Output
- Internally-Trimmed Bandgap Reference
- Up to 500-kHz Operation
- Create a Custom Design Using the UCx84xA With the WEBENCH® Power Designer
UC3842AN Applications
- Switch Mode Power Supplies (SMPS)
- DC-DC Converters
- Power Modules
- Industrial PSU
- Battery Operated PSU
UC3842AN Datasheet
Click the link given below to download the datasheet.
UC3842AN-Datasheet
UC3842AN Product Attributes
Physical |
Case/Package |
PDIP |
Number of Pins |
8 |
Weight |
528.605208 mg |
|
Technical |
Duty Cycle |
1 |
Fall Time |
50 ns |
Frequency |
450 kHz |
Input Current |
11 mA |
Max Duty Cycle |
1 |
Max Frequency |
500 kHz |
Max Input Voltage |
25 V |
Max Operating Temperature |
70 ℃ |
Max Output Current |
1 A |
Max Output Voltage |
13.5 V |
Max Power Dissipation |
1 W |
Max Supply Voltage |
30 V |
Min Operating Temperature |
0 ℃ |
Min Supply Voltage |
12 V |
Nominal Input Voltage |
15 V |
Number of Channels |
1 |
Number of Outputs |
1 |
Output Current |
1 A |
Output Voltage |
5 V |
Power Dissipation |
1 W |
Reference Voltage |
5 V |
Rise Time |
50 ns |
Schedule B |
8542390000 |
Switching Frequency |
500 kHz |
Termination |
Through Hole |
Tolerance |
0.02 |
Topology |
Flyback, Boost, Buck-Boost |
|
Dimensions |
Height |
5.08 mm |
Length |
9.81 mm |
Thickness |
3.9 mm |
Width |
6.35 mm |
|
Compliance |
Lead Free |
Lead Free |
Radiation Hardening |
No |
REACH SVHC |
No SVHC |
UC3842A, PWM Controllers With Low Start-up Current
UC3842M, Current-Mode PWM Controller
UC3843A, Current Mode PWM Controller
UC3844A, Current Mode PWM Controller
UC3845A, Current Mode PWM Controller
PT2202, Low-Cost Current Mode PWM Controller
PT2201, Current Mode PWM Controller
NCP5322A, Two-Phase Buck Controller With Integrated Gate Drivers And 5-Bit DAC
ISL6556B, Optimized Multiphase PWM Controller With 6-Bit DAC And Programmable Internal Temperature Compensation For VR10.X Application
MIC2169, MIC2169 500kHz PWM Synchronous Buck Control IC
ISL65426MREP, Enhanced Product (EP) 6.0A Dual Synchronous Buck Regulator With Integrated MOSFETs
UCC1570, Low Power Pulse Width Modulator
HIP6019B, Advanced Dual PWM And Dual Linear Power Control
UC3842AN VS UC3842N
Source Content uid |
UC3842AN |
UC3842N |
Rohs Code |
No |
Yes |
Part Life Cycle Code |
Obsolete |
Obsolete |
Ihs Manufacturer |
ON SEMICONDUCTOR |
FAIRCHILD SEMICONDUCTOR CORP |
Part Package Code |
DIP |
DIP |
Package Description |
DIP, DIP8,.3 |
DIP, DIP8,.3 |
Pin Count |
8 |
8 |
Reach Compliance Code |
not_compliant |
compliant |
ECCN Code |
EAR99 |
EAR99 |
HTS Code |
8542.39.00.01 |
8542.39.00.01 |
Analog IC - Other Type |
SWITCHING CONTROLLER |
SWITCHING CONTROLLER |
Control Mode |
CURRENT-MODE |
CURRENT-MODE |
Control Technique |
PULSE WIDTH MODULATION |
PULSE WIDTH MODULATION |
Input Voltage-Max |
30 V |
30 V |
Input Voltage-Min |
11.5 V |
12 V |
Input Voltage-Nom |
15 V |
15 V |
JESD-30 Code |
R-PDIP-T8 |
R-PDIP-T8 |
JESD-609 Code |
e0 |
e3 |
Length |
9.78 mm |
9.2 mm |
Number of Functions |
1 |
1 |
Number of Terminals |
8 |
8 |
Operating Temperature-Max |
70 °C |
70 °C |
Operating Temperature-Min |
- |
- |
Output Current-Max |
1 A |
1 A |
Package Body Material |
PLASTIC/EPOXY |
PLASTIC/EPOXY |
Package Code |
DIP |
DIP |
Package Equivalence Code |
DIP8,.3 |
DIP8,.3 |
Package Shape |
RECTANGULAR |
RECTANGULAR |
Package Style |
IN-LINE |
IN-LINE |
Peak Reflow Temperature (Cel) |
NOT SPECIFIED |
NOT APPLICABLE |
Qualification Status |
Not Qualified |
Not Qualified |
Seated Height-Max |
4.45 mm |
5.08 mm |
Surface Mount |
NO |
NO |
Switcher Configuration |
SINGLE |
SINGLE |
Switching Frequency-Max |
500 kHz |
500 kHz |
Technology |
BIPOLAR |
BIPOLAR |
Temperature Grade |
COMMERCIAL |
COMMERCIAL |
Terminal Finish |
Tin/Lead (Sn/Pb) |
Matte Tin (Sn) |
Terminal Form |
THROUGH-HOLE |
THROUGH-HOLE |
Terminal Pitch |
2.54 mm |
2.54 mm |
Terminal Position |
DUAL |
DUAL |
Time@Peak Reflow Temperature-Max (s) |
NOT SPECIFIED |
NOT APPLICABLE |
Width |
7.62 mm |
7.62 mm |
Base Number Matches |
7 |
5 |
Manufacturer
Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globally. It is one of the top 10 semiconductor companies worldwide based on sales volume.The company's focus is on developing analog chips and embedded processors, which account for more than 80% of its revenue.TI also produces TI digital light processing technology and education technology products including calculators, microcontrollers and multi-core processors. The company holds 45,000 patents worldwide as of 2016.
Using Warning
Note: Please check their parameters and pin configuration before replacing them in your circuit.
FAQ about UC3842AN
Is the uc3842 IC a current mode controller?
Note: Complete Technical Details can be found at the UC3842 datasheet given at the end of this page. The UC3842 IC is a current Mode PWM Controller, meaning it can be used to provide a constant current by varying the output voltage to the load.
Is the uc3842 output driver biased to a high impedance?
During UVLO, the UC3842 output driver is biased to a high impedance state. However, leakage currents (up to 10 µA), if not shunted to ground, could pull high the gate of a POWERMOS. A 100 k Ω shunt, as showing in figure 6, will hold the gate voltage below 1V. APPLICATION NOTE 3/16
What is the under voltage lockout on uc3842?
UNDER-VOLTAGE LOCKOUT (UVLO) This circuit insures that VCCis adequate to make the UC3842 fully operational before enabling the output stage. Figure 5a shows that the UVLO turn-on and turn-off thresholds are fixed internally at 16 V and 10 V respectively. The 6 V hysteresis prevents VCC oscillations during power sequencing.
How is the peak current determined in uc3842?
UC3842 Block Diagram. Current limiting is simplified with current-mode con- trol. Pulse-by-pulse limiting is, of course, inherent in the control scheme. Furthermore, an upper limit on the peak current can be established by simply clam- ping the error voltage.
What is the use of PWM in SMPS?
PWM (Pulse Width Modulated) power supplies are a type of switching power supply. Pulse Width Modulation is generally used to help regulate the voltage in a switching power supply. This is necessary when the current demand on the power supply or the charging system's supply voltage is not constant.
How is power control done using PWM?
Pulse-width modulation (PWM) is a commonly used technique for controlling power made practical by modern electronic power switches. The average value of voltage (and current) fed to the load is controlled by turning the (transistor) switch between supply and load on and off at a fast pace.
What is the advantage of using SMPS?
The device is used in SMPS is compact and very small in size. The manufacturing cost is reduced. Provide isolation between multiple output. Low power wastage.
How does SMPS power supply works?
SMPS works by turning the main power on and off at a high speed to reduce the voltage. In such a case the reduction in voltage depends on the ratio of time and off time. Switching happens very quickly, 10,000 times or faster per second.
Why are PWM controllers preferred?
Pulse width modulation is a great method of controlling the amount of power delivered to a load without dissipating any wasted power. The above circuit can also be used to control the speed of a fan or to dim the brightness of DC lamps or LED's.
What is PWM in power supply?
Pulse Width Modulation (PWM), also known as pulse-duration modulation (PDM), is a technique for reducing the average power in an Alternating Current (AC) signal. Effectively chopping off parts of the waveform reduces the average voltage without affecting the base frequency of the signal.