mc44602 ON Semiconductor, mc44602 Datasheet - Page 14

• Manufacturer Part Number: mc44602
• Description: High Performance Current Mode Controller
• Manufacturer: ON Semiconductor

14
4, 5, 12, 13
Pin
10
14
15
16
11
1
2
3
6
7
8
9
Voltage Feedback Input
Current Sense Input
Load Detect Input
Compensation
Source Output
Sink Ground
Sink Output
Sync Input
Function
Ground
R T /C T
V CC
V ref
V C
PIN FUNCTION DESCRIPTION
This pin is the Error Amplifier output and is made available for loop compensation.
A voltage indicating a severe overload or short circuit condition at any output of the
switching power supply is connected to this input. The Oscillator is controlled by this
information making the power supply short circuit proof.
This is the inverting input of the Error Amplifier and the noninverting input of the
Foldback Amplifier. It is normally connected to the switching power supply output
through a resistor divider.
The Sink Ground pins form a single power return that is typically connected back to the
power source on a separate path from Pin 9 Ground, to reduce the effects of switching
transient noise on the control circuitry. These pins can be used to enhance the package
power capabilities (Figure 14). The Sink Output low state (V OL ) can be modified by
applying a negative voltage to these pins with respect to Ground (Pin 9) to optimize
turn–off of a bipolar junction transistor.
A voltage proportional to inductor current is connected to this input. The PWM uses this
information to terminate conduction of the output switch transistor.
A narrow rectangular waveform applied to this input will synchronize the Oscillator. A dc
voltage within the range of 3.2 V to 5.5 V will inhibit the Oscillator.
The Oscillator frequency and maximum Output duty cycle are programmed at this pin by
connecting resistor R T to V ref and capacitor C T to ground.
This pin is the control circuitry ground and is typically connected back to the power
source on a separate path from the Sink Ground (Pins 4, 5, 12, 13).
Peak currents up to 1.5 A are sunk by this output suiting it ideally for turning–off a bipolar
junction transistor. The output switches at one–half the oscillator frequency.
Peak currents up to 1.0 A are sourced by this output suiting it ideally for turning–on a
bipolar junction transistor. The output switches at one–half the oscillator frequency.
The Output high state (V OH ) is set by the voltage applied to this pin. With a separate
connection to the power source, it can reduce the effects of switching transient noise on
the control circuitry.
This pin is the positive supply of the control IC. The minimum operating voltage range
after startup is 11 V to 18 V.
This is the 5.0 V reference output. It provides charging current for capacitor C T through
resistor R T and can be used to bias any additional system circuitry.
MC44602
Description
MOTOROLA ANALOG IC DEVICE DATA