Document Outline
- Introduction
- 33998 Simplified Application Diagram
- 33998 Simplified Block Diagram
- Pin Function Description
- Maximum Ratings
- Static Electrical Characteristics
- Dynamic Electrical Characteristics
- Timing Diagrams
- System/Application Information
- Introduction
- Functional Pin Description
- Applications
- Package Dimensions
MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
Motorola, Inc. 2003
33998 Simplified Application Diagram
Document order number: MC33998/D
Rev 1.0, 03/2003
33998
Advance Information
Switching Power Supply with Linear
Regulators
The 33998 is a medium-power, multi-output power supply integrated circuit
that is capable of operating over a wide input voltage range, from 6.0 V up to
26.5 V with 40 V transient capability. It incorporates a sensorless current
mode control step-down switching controller regulating directly to 5.0 V. The
2.6 V linear regulator uses an external pass transistor to reduce the 33998
power dissipation. The 33998 also provides a 2.6 V linear standby regulator
and two 5.0 V sensor supply outputs protected by internal low-resistance
LDMOS transistors.
There are two separate enable pins for the main and sensor supply outputs
and standard supervisory functions such as resets with power-up reset delay.
The 33998 provides proper power supply sequencing for advanced
microprocessor architectures such as the Motorola MPC5xx and 683xx
microprocessor families.
Features
Operating Voltage Range 6.0 V up to 26.5 V (40 V transient)
Step-Down Switching Regulator Output V
DDH
= 5.0 V @ 1400 mA (total)
Linear Regulator with External Pass Transistor V
DDL
= 2.6 V @ 400 mA
Low-Power Standby Linear Regulator V
KAM
= 2.6 V @ 10 mA
Two 5.0 V @ 200 mA (typical) Sensor Supplies V
REF
Protected Against
Short-to-Battery and Short-to-Ground with Retry Capability
Undervoltage Shutdown on the V
DDL
, V
DDH
Outputs with Retry Capability
Reset Signals
Power-Up Delay
Enable Pins for Main Supplies (EN) and Sensor Supplies (SNSEN)
Power Sequencing for Advanced Microprocessor Architectures
SOIC-24WB Package
SNSEN
VREF1
5.0 V
VPWR
KA_VPWR
GND
33998
EN
VSW
VDDH
DRVL
FBL
PWROK
VKAM
VKAMOK
VREF2
5.0 V
5.0 V
2.6 V
2.6 V
MCU
VDDH
VDDL
VKAM
ORDERING INFORMATION
Device
Temperature
Range (T
A
)
Package
MC33998DW/R2
-40C to 125C
24 SOICW
DW SUFFIX
24-LEAD SOICW
CASE 751E
POWER SUPPLY
INTEGRATED CIRCUIT
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33998
MOTOROLA ANALOG INTEGRATED CIRCUIT DEVICE DATA
2
Figure 1. 33998 Simplified Block Diagram
SNSEN
VPW R
KA_VPW R
PGND
339 98
EN
VSW
VDDH
DRVL
FBL
PWROK
V KAM
VKAMOK
V bg
VRE F1
VRE F2
I -lim
Ramp
O sc
S oft
Start
Logic
&
Latch
PwrOK
VkamOK
POR
2.6V
Lin ear
Re gulat or
Driver
2. 6V
Standby
Reg.
B andgap
Voltage
Reference
Charge
Pump
VREF1
Reg.
VREF2
Reg.
Vbg
Vbg
CRES
VSUM
FBKB
En able
Co ntrol
E nb
Sn senb
5.0 V
5.0 V
2.6 V
5.0 V
2.6 V
Snsenb
S nsenb
Enb
Enb
Enb
Retry
Retry
Drive
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Freescale Semiconductor, Inc.
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MOTOROLA ANALOG INTEGRATED CIRCUIT DEVICE DATA
33998
3
PIN FUNCTION DESCRIPTION
Pin
Pin Name
Description
1
VKAMOK
Keep-Alive Output Monitoring. This pin is an "open-drain" output that will be used with a discrete pull-up resistor
to V
KAM
. When the supply voltage to the 33998 is disconnected or lost, the VKAMOK signal goes low.
2
KA_V
PWR
Keep Alive Power Supply Pin. This supply pin is used in modules that have both direct battery connections and
ignition switch activated connections.
3
C
RES
Reservoir Capacitor. This pin is tied to an external "reservoir capacitor" for the internal charge pump.
4
V
PWR
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.
58
GND
Ground of the integrated circuit.
9
V
SW
Internal P-Channel Power MOSFET Drain. V
SW
is the "switching node" of the voltage buck converter. This pin
is connected to the V
PWR
pin by an integrated p-channel MOSFET.
10
PWROK
Power OK Reset Pin. This pin is an "open-drain" output that will be used with a discrete pull-up resistor to
V
KAM
, V
DDH
, or V
DDL
. When either V
DDH
or V
DDL
output voltage goes out of the regulation limits this pin is
pulled down.
11
FBKB
Step-Down Switching Regulator Feedback Pin. The FBKB pin is the V
DDH
feedback signal for the switching
regulator.
12
V
SUM
Error Amplifier "Summing Node". The V
SUM
pin is connected to the inverting input of the error amplifier. This
node is also the "common" point of the integrated feedback resistor divider.
13
DRVL
Drive for V
DDL
(2.6 V) Regulator. The DRVL pin drives the base of an external NPN pass transistor for the
V
DDL
linear post regulator. The collector of the VDDL pass transistor is connected to V
DDH
. An example of a
suitable pass transistor is BCP68.
14
FBL
Feedback for V
DDL
(2.6 V) Regulator. The FBL pin is the voltage feedback sense signal from the V
DDL
(2.6 V)
linear post regulator.
15
V
DDH
V
DDH
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 V
DDH
pin is supplied from the switching regulator output, capable of providing 5.0 V
@ 1400 mA total output current.
16
V
REF2
Sensor Supply #2 Output. The V
REF2
pin is sensor supply output #2.
1720
GND
Ground of the integrated circuit.
21
V
REF1
Sensor Supply #1 Output. The V
REF1
pin is sensor supply output #1.
V
KAM
GND
GND
GND
GND
V
REF2
V
DDH
FBL
DRVL
EN
SNSEN
V
REF1
VKAMOK
GND
GND
GND
GND
V
SW
PWROK
V
SUM
KA_V
PWR
C
RES
V
PWR
FBKB
5
6
7
8
9
10
11
12
2
3
4
24
20
19
18
17
16
15
13
23
22
21
14
1
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Freescale Semiconductor, Inc.
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33998
MOTOROLA ANALOG INTEGRATED CIRCUIT DEVICE DATA
4
22
SNSEN
Sensor Supply Enable Input. The SNSEN pin is an input, which enables the V
REF1
and V
REF2
supplies. It
allows the control module hardware/software to shut down the sensor supplies.
23
EN
Enable Input. The EN pin is an input, which enables the main switching regulator and all other functions. When
this pin is low, the power supply is in a low quiescent state.
24
V
KAM
Keep-Alive (standby) 2.6 V Regulator Output. This is a 2.6 V low quiescent, low dropout regulator for Keep
Alive memory.
PIN FUNCTION DESCRIPTION (continued)
Pin
Pin Name
Description
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Freescale Semiconductor, Inc.
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MOTOROLA ANALOG INTEGRATED CIRCUIT DEVICE DATA
33998
5
MAXIMUM RATINGS
All voltages are with respect to ground unless otherwise noted.
Rating
Symbol
Value
Unit
Main Supply Voltage
V
PWR
-0.3 to 45
V
Keep-Alive Supply Voltage
KA_V
PWR
-0.3 to 45
V
Switching Node
V
SW
-0.5 to 45
V
5.0 V Input Power
V
DDH
-0.3 to 6.0
V
Sensor Supply
V
REF1
V
REF2
-0.3 to 18
-0.3 to 18
V
Keep-Alive Supply Voltage
V
KAM
-0.3 to 6.0
V
Maximum Voltage at Logic I/O Pins
EN
SNSEN
PWROK
VKAMOK
-0.3 to 6.0
-0.3 to 6.0
-0.3 to 6.0
-0.3 to 6.0
V
Charge Pump Reservoir Capacitor Voltage
C
RES
-0.3 to 18
V
Error Amplifier Summing Node
V
SUM
-0.3 to 6.0
V
Switching Regulator Output Feedback
FBKB
-0.3 to 6.0
V
V
DDL
Base Drive
DRVL
-0.3 to 6.0
V
V
DDL
Feedback
FBL
-0.3 to 6.0
V
ESD Voltage
Human Body Model (all pins) (Note 1)
Machine Model (all pins) (Note 2)
V
ESD1
V
ESD2
500
100
V
Power Dissipation (T
A
= 25
C) (Note 3)
P
D
800
mW
Thermal Resistance, Junction to Ambient (Note 4), (Note 5)
R
J-A
60
C/W
Thermal Resistance, Junction to Board (Note 6)
R
J-B
20
C/W
Operational Package Temperature [Ambient Temperature] (Note 7)
T
A
-40 to 125
C
Operational Junction Temperature
T
J
-40 to 150
C
Storage Temperature
T
STG
-55 to 150
C
Lead Soldering Temperature (Note 8)
T
S
260
C
Notes
1.
ESD1 testing is performed in accordance with the Human Body Model (C
ZAP
=100 pF, R
ZAP
=1500
).
2.
ESD2 testing is performed in accordance with the Machine Model (C
ZAP
=200 pF, R
ZAP
=0
)
3.
Maximum power dissipation at indicated junction temperature.
4.
Junction temperature is a function of on-chip power dissipation, package thermal resistance, mounting site (board) temperature, ambient
temperature, air flow, power dissipation of other components on the board, and board thermal resistance.
5.
Per SEMI G38-87 and JEDEC JESD51-2 with the single layer board horizontal.
6.
Thermal resistance between the die and the printed circuit board per JEDEC JESD51-8. Board temperature is measured on the top surface
of the board near the package.
7.
The limiting factor is junction temperature, taking into account the power dissipation, thermal resistance, and heat sinking.
8.
Lead soldering temperature limit is for 10 seconds maximum duration. Not designed for immersion soldering. Exceeding these limits may
cause malfunction or permanent damage to the device.
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Freescale Semiconductor, Inc.
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