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TL3842P Current Mode PWM Controller

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Pin-out Configuration

Two types of TL3842P packages are available on the basis of pin configuration and body size.

Device/IC

Package

Body Size

 

TL3842

SOIC (8)

4.90 mm × 3.91 mm

SOIC (14)

8.65 mm × 3.91 mm

PDIP (8)

9.81 mm × 6.35 mm

D-Package SOIC (14)

Pin Number

Pin Name

Description

1

COMP

Compensation pin for error amplification

2

NC

Internal connection, do not connect

3

VFB

Error amplifier input

4

NC

Internal connection, do not connect

5

ISENSE

Current sensor

6

NC

Internal connection, do not connect

7

RT/CT

Oscillator RC input

8

POWER_GROUND

PWM Output, Ground terminal

9

GND

Ground terminal for power supply

10

OUTPUT

PWM Output

11

Vc

PWM Output , Positive Supply

12

Vcc

Voltage supply for the device

13

NC

Internal connection, do not connect

14

REF

Voltage reference of oscillator

D or P- Package SOIC (8) or PDIP (8)

Pin Number

Pin Name

Description

1

COMP

Compensation pin for error amplification

2

VFB

Error amplifier input

3

ISENSE

Current sensor

4

RT/CT

Oscillator RC input

5

GND

Ground terminal for power supply

6

OUTPUT

PWM Output

7

Vcc

Voltage supply for the device

8

REF

Voltage reference of oscillator

 

Features

  • Precise frequency control
  • Low start up current (less than 1mA)
  • Latching PWM for cycle to cycle current limiting
  • Enhanced load response characteristics
  • Adjustable ramp compensation
  • Continuous retry after fault timeout
  • Soft start with maximum peak switch current
  • Optimized for off line and DC to DC converters
  • Internally trimmed reference with under voltage lockout
  • Low startup and operating current
  • Current Mode Operation to 500 kHz
  • Error amplifier with low output resistance
  • Automatic feed forward compensation
  • High current totem pole output

 

Alternative Current Mode Controller

TL2842, TL2843, TL2844, TL2845, TL3843, TL3844, TL3845

 

TL3842p Current Mode PWM Controller Equivalent

TL3843p

 

Where to use TL3842p

If you are looking for DC to DC conversion regardless of buck or boost topology TL3842p finds its applications there. Usually microcontrollers and digital electronics requires a higher current at lower operating voltages so it becomes important to reduce the induction losses of power supply by making the resistance of the current sensing element as low as possible which is achieved by using a current mode controller. Current mode controllers are highly reliable with fast cycle to cycle current sensing for output short circuit and overload protection, so they can be used for the protection purposes as well. Current mode controllers are being used in digital cameras, Bluetooth devices, cellular phones, auxiliary power supplies.

 


How to use TL3842p

Using TL3842p current mode PWM controller is very simple and straightforward. Positive power supply ranging from 2.5 Volts to 30 Volts should be applied at the Vcc terminal of the integrated circuit. Output range of the output PWM is 0 to 30 Volts. Timing and bypass capacitors should be connected close to the GND terminal in a single point ground (all the grounds of the circuit should be made common). Combination of transistor and variable resistor should be used to supply adjustable ramp to the ISENSE terminal. External compensation components for stability should also be placed close to the IC. Surface mount components are recommended here as well. These components should not be located very much close to the inductor because it will induce a magnetic field around it. The common ground of the complete network should be placed at the ground terminal of the device to make a reference point. While using the network with the TL3842p it should be observed that the output current does not exceed 25 mA that is the maximum bearable current by the device. Tl3842p has a very good frequency response. It can carry out smooth function for the frequency ranging from 100 kHz to 500 kHz.

 

Applications

  • Wireless networking
  • Mobile Phones
  • Media Players
  • Power Driver Supplies
  • Bluetooth Devices
  • Auxiliary Power Supplies
  • Portable Devices
  • LED Light Engines
  • Switching regulators of any polarity
  • Transformer coupled DC to DC Convertors

 

 

2D Model

2D Model of TL3842 Current Mode Controller