MC33092A
6
MOTOROLA ANALOG IC DEVICE DATA
PIN FUNCTION DESCRIPTION
Pin No.
Function
Description
1
FB
This pin provides a filtered result of the Sense input (if the Sense input is used) or the Supply
Regulation input (if the Sense input is not used).
2
Sense
The Sense input is a remote (Kelvin), low current battery voltage reference input used to give an
accurate representation of the true battery voltage. This input is also used to monitor overvoltage or
load dump conditions.
3
Lamp Collector and
Power–Up/Down
This pin connects to the collector of the transistor (Q2) used to drive the fault lamp. It is also used to
sense a closed ignition switch (voltage sense) which then turns power on to the IC.
4
Lamp Base
The Lamp Base pin provides base current to the fault lamp drive transistor (Q2).
5
Ground
Grounded to provide a ground return for the fault lamp control logic circuit.
6, 15
Ground
IC ground reference pins.
7
Oscillator Adjust
A resistor to ground on this pin adjusts the internal oscillator frequency (see Figure 6).
8
* Vref
This is a test point for the 1.1 V to 1.4 V reference voltage. It has a zero temperature coefficient. The
reference is used internally for phase signal and undervoltage detection.
9
* Oscillator
Test point for checking the operation of the internal oscillator.
10
Phase
The Phase input detects the existence of a magnetic field rotating within the alternator.
11
Rate
The Rate pin is used to select a slow mode (floating) or fast mode (ground) Load
Response Control recovery rate.
12
Supply Regulation
The voltage on the Supply Regulation pin is used as a representation of the alternator output
voltage. This input also used to monitor overvoltage or load dump conditions.
13
VCC3
VCC1
Ground
Positive supply for the internal Charge Pump.
14
Positive supply for the entire IC except for the Charge Pump.
15, 6
Ground reference for the IC.
16
N/C
No connection.
17
Gate
Controls the Gate of the MOSFET used to energize the field winding.
18
Source
Field winding control MOSFET source reference.
19
Undervoltage
If the voltage at this pin goes below 1.0 V, the fault lamp is guaranteed to turn on. The IC will
continue to function, but with limited performance.
20
* Vref
Test point for the 1.7 V to 2.3 V Bandgap reference voltage. This voltage has a negative
temperature coefficient of approximately –11 mV/
°
C.
*
NOTE:
Pins 8, 9 and 20 are test points only.