MC33998 Ver la hoja de datos (PDF) - Freescale Semiconductor
Número de pieza
componentes Descripción
Fabricante
MC33998 Datasheet PDF : 20 Pages
| |||
PIN CONNECTIONS
PIN CONNECTIONS
VKAMOK
1
KA_VPWR
2
CRES
3
VPWR
4
GND
5
GND
6
GND
7
GND
8
VSW
9
PWROK
10
FBKB
11
VSUM
12
24 VKAM
23 EN
22 SNSEN
21 VREF1
20 GND
19 GND
18 GND
17 GND
16 VREF2
15 VDDH
14 FBL
13 DRVL
Table 1. Pin Definitions
Pin Number
Pin
Name
1
VKAMOK
2
KA_VPWR
3
CRES
4
VPWR
5–8
GND
9
VSW
10
PWROK
11
FBKB
12
VSUM
13
DRVL
14
FBL
15
VDDH
16
17 – 20
21
VREF2
GND
VREF1
Figure 3. 33998 Pin Connections
Definition
Keep-Alive Output Monitoring. This pin is an "open-drain" output that will be used with a discrete pull-up
resistor to VKAM. When the supply voltage to the 33998 is disconnected or lost, the VKAMOK signal goes
low.
Keep Alive Power Supply Pin. This supply pin is used in modules that have both direct battery connections
and ignition switch activated connections.
Reservoir Capacitor. This pin is tied to an external "reservoir capacitor" for the internal charge pump.
Power Supply Pin. Main power input to the IC. This pin is directly connected to the switching regulator
power MOSFET. In automotive applications this pin must be protected against reverse battery conditions
by an external diode.
Ground of the integrated circuit.
Internal P-Channel Power MOSFET Drain. VSW is the "switching node" of the voltage buck converter. This
pin is connected to the VPWR pin by an integrated p-channel MOSFET.
Power OK Reset Pin. This pin is an "open-drain" output that will be used with a discrete pull-up resistor to
VKAM, VDDH, or VDDL. When either VDDH or VDDL output voltage goes out of the regulation limits this
pin is pulled down.
Step-Down Switching Regulator Feedback Pin. The FBKB pin is the VDDH feedback signal for the
switching regulator.
Error Amplifier "Summing Node". The VSUM pin is connected to the inverting input of the error amplifier.
This node is also the "common" point of the integrated feedback resistor divider.
Drive for VDDL (2.6 V) Regulator. The DRVL pin drives the base of an external NPN pass transistor for the
VDDL linear post regulator. The collector of the VDDL pass transistor is connected to VDDH. An example
of a suitable pass transistor is BCP68.
Feedback for VDDL (2.6 V) Regulator. The FBL pin is the voltage feedback sense signal from the VDDL
(2.6 V) linear post regulator.
VDDH is an input supply pin providing power for the buffered sensor supplies and the drive circuitry for the
2.6 V linear power regulator. The VDDH pin is supplied from the switching regulator output, capable of
providing 5.0 V @ 1400 mA total output current.
Sensor Supply #2 Output. The VREF2 pin is sensor supply output #2.
Ground of the integrated circuit.
Sensor Supply #1 Output. The VREF1 pin is sensor supply output #1.
33998
3
Analog Integrated Circuit Device Data
Freescale Semiconductor
Share Link: 