UC3842BNG ON Semiconductor, UC3842BNG Datasheet - Page 7

• Manufacturer Part Number: UC3842BNG
• Description: IC CTLR CURRENT MODE 8-DIP
• Manufacturer: ON Semiconductor
• Type: Pulse Width Modulator Controllerr

Specifications of UC3842BNG

• Pwm Type: Current Mode
• Number Of Outputs: 1
• Frequency - Max: 275kHz
• Duty Cycle: 96%
• Voltage - Supply: 11.5 V ~ 25 V
• Buck: No
• Boost: Yes
• Flyback: Yes
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: Yes
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 8-DIP (0.300", 7.62mm)
• Frequency-max: 275kHz
• Duty Cycle (max): 96 % (Typ)
• Output Voltage: 4.9 V to 5.1 V
• Output Current: 1000 mA (Max)
• Mounting Style: Through Hole
• Switching Frequency: 500 KHz
• Operating Supply Voltage: 30 V
• Maximum Operating Temperature: 70 C
• Fall Time: 50 ns
• Minimum Operating Temperature: 0 C
• Rise Time: 50 ns
• Synchronous Pin: No
• Topology: Boost or Flyback or Forward
• Current, Input Bias: -2 μA
• Current, Output: +12 mA (Sink), -1 mA (Source)
• Current, Supply: 0.3 mA
• Frequency, Oscillator: 250 kHz
• Package Type: PDIP-8
• Power Dissipation: 1.25 W
• Regulation, Line: 2 mV
• Regulation, Load: 3 mV
• Regulator Type: DC-DC
• Temperature, Operating, Range: 0 to +70 °C
• Time, Fall: 50 ns
• Time, Rise: 50 ns
• Voltage, Gain: 3 V/V
• Voltage, Input: 2.5 V
• Voltage, Noise: 50 μV
• Voltage, Output: 5 V
• Voltage, Output, High: 6.2 V
• Voltage, Output, Low: 0.8 V
• Voltage, Supply: 30 V
• Voltage, Supply, Rejection Ratio: 70 dB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: UC3842BNGOS

PIN FUNCTION DESCRIPTION
8−Pin
- 2.0
-1.0
3.0
2.0
1.0
1
2
3
4
5
6
7
8
0
0
0
Ä Ä Ä
14−Pin
2,4,6,1
V
Ä Ä Ä Ä
Ä Ä Ä Ä
10
12
14
11
Figure 16. Output Cross Conduction
Figure 14. Output Saturation Voltage
CC
1
3
5
7
8
9
3
T
A
Ä Ä Ä
Ä Ä Ä
T
= 25°C
A
200
= - 55°C
I
O
Compensation
, OUTPUT LOAD CURRENT (mA)
versus Load Current
Feedback
Function
Voltage
Current
Ground
Output
Sense
Power
R
Ä Ä Ä Ä Ä
Ä Ä Ä Ä Ä
Ä Ä Ä Ä
Ä Ä Ä Ä
Ä Ä Ä Ä
Ä Ä Ä Ä
GND
GND
V
V
NC
T
V
CC
/C
ref
Source Saturation
(Load to Ground)
C
Sink Saturation
(Load to V
T
T
100 ns/DIV
A
= - 55°C
400
CC
This pin is the Error Amplifier output and is made available for loop compensation.
This is the inverting input of the Error Amplifier. It is normally connected to the switching power
supply output through a resistor divider.
A voltage proportional to inductor current is connected to this input. The PWM uses this
information to terminate the output switch conduction.
The Oscillator frequency and maximum Output duty cycle are programmed by connecting resistor
R
This pin is the combined control circuitry and power ground.
This output directly drives the gate of a power MOSFET. Peak currents up to 1.0 A are sourced
and sunk by this pin.
This pin is the positive supply of the control IC.
This is the reference output. It provides charging current for capacitor C
This pin is a separate power ground return that is connected back to the power source. It is used
to reduce the effects of switching transient noise on the control circuitry.
The Output high state (V
source connection, it can reduce the effects of switching transient noise on the control circuitry.
This pin is the control circuitry ground return and is connected back to the power source ground.
No connection. These pins are not internally connected.
)
T
to V
Ä Ä Ä Ä Ä
Ä Ä Ä Ä Ä
Ä Ä Ä Ä Ä
80 ms Pulsed Load
ref
Ä Ä Ä
Ä Ä Ä
Ä Ä
GND
600
120 Hz Rate
T
and capacitor C
V
V
C
T
A
CC
A
CC
L
= 25°C
= 25°C
= 15 pF
= 15 V
= 30 V
http://onsemi.com
800
OH
T
) is set by the voltage applied to this pin. With a separate power
to ground. Operation to 500 kHz is possible.
7
90%
10%
25
20
15
10
5
0
0
Figure 17. Supply Current versus Supply Voltage
Description
Figure 15. Output Waveform
10
V
CC
, SUPPLY VOLTAGE (V)
50 ns/DIV
20
T
through resistor R
Ä Ä Ä Ä
Ä Ä Ä Ä
Ä Ä Ä Ä
Ä Ä Ä Ä
R
C
V
I
T
Sense
A
T
T
FB
= 25°C
= 10 k
= 3.3 nF
= 0 V
30
V
C
T
= 0 V
A
CC
L
= 25°C
= 1.0 nF
= 15 V
T
.
40