MC34167TH [ONSEMI]
POWER SWITCHING REGULATORS; 电源开关稳压器
| 型号： | MC34167TH |
| 厂家： | 
ONSEMI |
| 描述： | POWER SWITCHING REGULATORS |
| 文件： | 总16页 (文件大小：412K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Order this document by MC34167/D
The MC34167, MC33167 series are high performance fixed frequency
power switching regulators that contain the primary functions required for
dc–to–dc converters. This series was specifically designed to be
incorporated in step–down and voltage–inverting configurations with a
minimum number of external components and can also be used cost
effectively in step–up applications.
POWER SWITCHING
REGULATORS
These devices consist of an internal temperature compensated
reference, fixed frequency oscillator with on–chip timing components,
latching pulse width modulator for single pulse metering, high gain error
amplifier, and a high current output switch.
SEMICONDUCTOR
TECHNICAL DATA
Protective features consist of cycle–by–cycle current limiting,
undervoltage lockout, and thermal shutdown. Also included is a low power
standby mode that reduces power supply current to 36 µA.
TH SUFFIX
PLASTIC PACKAGE
CASE 314A
• Output Switch Current in Excess of 5.0 A
• Fixed Frequency Oscillator (72 kHz) with On–Chip Timing
• Provides 5.05 V Output without External Resistor Divider
• Precision 2% Reference
1
5
• 0% to 95% Output Duty Cycle
1
TV SUFFIX
PLASTIC PACKAGE
• Cycle–by–Cycle Current Limiting
• Undervoltage Lockout with Hysteresis
• Internal Thermal Shutdown
5
CASE 314B
Heatsink surface connected to Pin 3.
• Operation from 7.5 V to 40 V
• Standby Mode Reduces Power Supply Current to 36 µA
• Economical 5–Lead TO–220 Package with Two Optional Leadforms
T SUFFIX
PLASTIC PACKAGE
CASE 314D
2
• Also Available in Surface Mount D PAK Package
1
5
Pin 1. Voltage Feedback Input
2. Switch Output
3. Ground
4. Input Voltage/V
5. Compensation/Standby
CC
Simplified Block Diagram
(Step Down Application)
V
in
D2T SUFFIX
4
2
I
LIMIT
PLASTIC PACKAGE
CASE 936A
2
1
(D PAK)
Oscillator
5
S
R
Q
Heatsink surface (shown as terminal 6
in case outline drawing) is connected to Pin 3.
PWM
ORDERING INFORMATION
Operating
UVLO
Thermal
L
Temperature Range
Device
Package
Surface Mount
Straight Lead
Horiz. Mount
Vertical Mount
Surface Mount
Straight Lead
Horiz. Mount
Vertical Mount
Reference
MC33167D2T
MC33167T
EA
T
A
= –40° to +85°C
MC33167TH
MC33167TV
MC34167D2T
MC34167T
1
V
O
5.05 V/5.0 A
3
T
A
= 0° to + 70°C
5
MC34167TH
MC34167TV
This device contains 143 active transistors.
Motorola, Inc. 1996
Rev 3
MC34167 MC33167
MAXIMUM RATINGS
Rating
Symbol
Value
40
Unit
V
Power Supply Input Voltage
Switch Output Voltage Range
V
CC
V
–2.0 to + V
V
O(switch)
in
Voltage Feedback and Compensation Input
Voltage Range
V
V
–1.0 to + 7.0
V
FB, Comp
Power Dissipation
Case 314A, 314B and 314D (T = +25°C)
P
D
Internally Limited
W
A
Thermal Resistance, Junction–to–Ambient
θ
θ
65
°C/W
°C/W
W
JA
JC
Thermal Resistance, Junction–to–Case
5.0
2
Case 936A (D PAK) (T = +25°C)
P
Internally Limited
A
D
JA
JC
Thermal Resistance, Junction–to–Ambient
θ
θ
70
°C/W
°C/W
Thermal Resistance, Junction–to–Case
5.0
Operating Junction Temperature
T
+150
°C
°C
J
Operating Ambient Temperature (Note 3)
MC34167
MC33167
T
A
0 to + 70
– 40 to + 85
Storage Temperature Range
T
stg
– 65 to +150
°C
ELECTRICAL CHARACTERISTICS (V
= 12 V, for typical values T = +25°C, for min/max values T is the operating ambient
CC
A
A
temperature range that applies [Notes 2, 3], unless otherwise noted.)
Characteristic
OSCILLATOR
Symbol
Min
Typ
Max
Unit
Frequency (V
= 7.5 V to 40 V)
T
T
A
= +25°C
f
OSC
65
62
72
–
79
81
kHz
CC
A
= T
to T
low
high
high
ERROR AMPLIFIER
Voltage Feedback Input Threshold
T
=+ 25°C
V
4.95
4.85
5.05
–
5.15
5.20
V
A
FB(th)
T
= T
to T
A
low
Line Regulation (V
CC
= 7.5 V to 40 V, T = +25°C)
Reg
line
–
–
0.03
0.15
80
0.078
1.0
–
%/V
µA
dB
V
A
Input Bias Current (V
= V
+ 0.15 V)
I
FB
FB(th)
CC
High State (I
IB
PSRR
Power Supply Rejection Ratio (V
= 10 V to 20 V, f = 120 Hz)
= 75 µA, V = 4.5 V)
60
Output Voltage Swing
V
OH
V
OL
4.2
–
4.9
1.6
–
1.9
Source
= 0.4 mA, V
FB
= 5.5 V)
Low State (I
Sink
FB
PWM COMPARATOR
Duty Cycle (V
= 20 V)
Maximum (V
= 0 V)
= 1.9 V)
DC
92
0
95
0
100
0
%
CC
FB
(max)
DC
Minimum (V
Comp
(min)
SWITCH OUTPUT
Output Voltage Source Saturation (V
= 7.5 V, I
= 5.0 A)
V
–
–
(V
CC
–1.5)
(V
–1.8)
100
V
µA
A
CC
= 40 V, Pin 2 = Gnd)
Source
sat
CC
Off–State Leakage (V
CC
I
0
sw(off)
Current Limit Threshold (V
CC
= 7.5 V)
I
5.5
6.5
8.0
pk(switch)
Switching Times (V
= 40 V, I = 5.0 A, L = 225 µH, T = +25°C)
pk
ns
CC
A
Output Voltage Rise Time
Output Voltage Fall Time
t
t
–
–
100
50
200
100
r
f
UNDERVOLTAGE LOCKOUT
Startup Threshold (V
Increasing, T = +25°C)
V
5.5
0.6
5.9
0.9
6.3
1.2
V
V
CC
A
th(UVLO)
Hysteresis (V
CC
Decreasing, T = +25°C)
V
H(UVLO)
A
TOTAL DEVICE
Power Supply Current (T = +25°C )
I
A
CC
Standby (V
= 12 V, V
< 0.15 V)
–
–
36
40
100
60
µA
mA
CC
Operating (V
Comp
= 40 V, Pin 1 = Gnd for maximum duty cycle)
CC
NOTES: 1. Maximum package power dissipation limits must be observed to prevent thermal shutdown activation.
2. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible.
3. T
= 0°C for MC34167
= – 40°C for MC33167
T
high
= + 70°C for MC34167
= + 85°C for MC33167
low
2
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
Figure 1. Voltage Feedback Input Threshold
versus Temperature
Figure 2. Voltage Feedback Input Bias
Current versus Temperature
5.25
5.17
5.09
5.01
4.93
4.85
100
80
60
40
20
0
V
= 12 V
CC
V
FB(th)
Max = 5.15 V
Typ = 5.05 V
Min = 4.95 V
V
V
= 12 V
CC
FB
= V
FB(th)
V
FB(th)
V
FB(th)
– 55
– 25
0
25
50
75
100
125
– 55
– 25
0
25
50
75
100
125
2.0
4.5
T , AMBIENT TEMPERATURE (
°C)
T , AMBIENT TEMPERATURE (°C)
A
A
Figure 3. Error Amp Open Loop Gain and
Phase versus Frequency
Figure 4. Error Amp Output Saturation
versus Sink Current
100
80
60
40
20
2.0
1.6
1.2
0.8
0.4
0
0
30
V
= 12 V
CC
V
R
= 3.25 V
Comp
= 100 k
= +25°C
L
Gain
T
A
60
90
Phase
120
V
V
T
= 12 V
= 5.5 V
= +25°C
CC
FB
A
0
150
180
– 20
10
100
1.0 k
10 k
100 k
1.0 M
10 M
0
0.4
0.8
1.2
1.6
f, FREQUENCY (Hz)
I
Sink
, OUTPUT SINK CURRENT (mA)
Figure 5. Oscillator Frequency Change
versus Temperature
Figure 6. Switch Output Duty Cycle
versus Compensation Voltage
4.0
0
100
80
V
T
= 12 V
CC
= +25°C
V
= 12 V
CC
A
60
– 4.0
– 8.0
– 12
40
20
0
– 55
– 25
0
25
50
75
100
125
1.5
2.0
2.5
3.0
3.5
4.0
V
, COMPENSATION VOLTAGE (V)
T , AMBIENT TEMPERATURE (
°C)
Comp
A
3
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
Figure 7. Switch Output Source Saturation
versus Source Current
Figure 8. Negative Switch Output Voltage
versus Temperature
0
– 0.5
–1.0
–1.5
– 2.0
0
– 0.2
– 0.4
– 0.6
– 0.8
V
Gnd
CC
V
= 12 V
CC
T
= +25°C
A
Pin 5 = 2.0 V
Pins 1, 3 = Gnd
Pin 2 Driven Negative
I
= 100 µA
sw
I
= 10 mA
sw
– 2.5
– 3.0
–1.0
–1.2
0
2.0
4.0
6.0
8.0
125
125
– 55
– 25
0
25
50
75
100
125
I
, SWITCH OUTPUT SOURCE CURRENT (A)
T , AMBIENT TEMPERATURE (°C)
Source
A
Figure 9. Switch Output Current Limit
Threshold versus Temperature
Figure 10. Standby Supply Current
versus Supply Voltage
7.2
6.8
6.4
160
120
80
40
0
Pin 4 = V
Pins 1, 3, 5 = Gnd
Pin 2 Open
= +25°C
CC
V
= 12 V
CC
Pins 1, 2, 3 = Gnd
T
A
6.0
5.6
– 55
– 25
0
25
50
75
C)
100
0
10
20
30
40
T , AMBIENT TEMPERATURE (
°
V
, SUPPLY VOLTAGE (V)
A
CC
Figure 11. Undervoltage Lockout
Thresholds versus Temperature
Figure 12. Operating Supply Current
versus Supply Voltage
6.5
6.0
5.5
5.0
4.5
50
40
30
20
10
0
Startup Threshold
V
Increasing
CC
Turn–Off Threshold
Decreasing
V
CC
Pin 4 = V
Pins 1, 3 = Gnd
Pins 2, 5 Open
CC
T
= +25
°C
A
4.0
– 55
40
– 25
0
25
50
75
C)
100
0
10
20
, SUPPLY VOLTAGE (V)
30
T , AMBIENT TEMPERATURE (
°
V
CC
A
4
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
Figure 13. MC34167 Representative Block Diagram
V
in
Current
Sense
4
+
Input Voltage/V
CC
C
in
Oscillator
S
C
T
Switch
Output
Q
R
2
Pulse Width
Modulator
Undervoltage
Lockout
PWM Latch
Thermal
Shutdown
L
5.05 V
Reference
+
Voltage
Feedback
Input
+
Error
Amp
100 µA
V
O
1
R
2
C
120
5
O
C
F
R
F
Gnd
Compensation
3
R
1
Sink Only
=
Positive True Logic
Figure 14. Timing Diagram
4.1 V
Timing Capacitor C
T
Compensation
2.3 V
ON
Switch Output
OFF
5
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
INTRODUCTION
converter output. If the converter design requires an output
The MC34167, MC33167 series are monolithic power
switching regulators that are optimized for dc–to–dc converter
applications. These devices operate as fixed frequency,
voltage mode regulators containing all the active functions
required to directly implement step–down and
voltage–inverting converters with a minimum number of
external components. They can also be used cost effectively
in step–up converter applications. Potential markets include
automotive, computer, industrial, and cost sensitive consumer
products. A description of each section of the device is given
below with the representative block diagram shown in
Figure 13.
voltage greater than 5.05 V, resistor R must be added to
1
form a divider network at the feedback input as shown in
Figures 13 and 18. The equation for determining the output
voltage with the divider network is:
R
R
2
1
V
1
5.05
out
External loop compensation is required for converter
stability. A simple low–pass filter is formed by connecting a
resistor (R ) from the regulated output to the inverting input,
2
and a series resistor–capacitor (R , C ) between Pins 1 and
F
F
5. The compensation network component values shown in
each of the applications circuits were selected to provide
stability over the tested operating conditions. The step–down
converter (Figure 18) is the easiest to compensate for
stability. The step–up (Figure 20) and voltage–inverting
(Figure 22) configurations operate as continuous conduction
flyback converters, and are more difficult to compensate. The
simplest way to optimize the compensation network is to
observe the response of the output voltage to a step load
Oscillator
The oscillator frequency is internally programmed to
72 kHz by capacitor C and a trimmed current source. The
charge to discharge ratio is controlled to yield a 95%
maximum duty cycle at the Switch Output. During the
discharge of C , the oscillator generates an internal blanking
pulse that holds the inverting input of the AND gate high,
disabling the output switch transistor. The nominal oscillator
peak and valley thresholds are 4.1 V and 2.3 V respectively.
T
T
change, while adjusting R and C for critical damping. The
F
F
final circuit should be verified for stability under four boundary
conditions. These conditions are minimum and maximum
input voltages, with minimum and maximum loads.
By clamping the voltage on the error amplifier output
(Pin 5) to less than 150 mV, the internal circuitry will be
placed into a low power standby mode, reducing the power
supply current to 36 µA with a 12 V supply voltage. Figure 10
illustrates the standby supply current versus supply voltage.
The Error Amplifier output has a 100 µA current source
pull–up that can be used to implement soft–start. Figure 17
Pulse Width Modulator
The Pulse Width Modulator consists of a comparator with
the oscillator ramp voltage applied to the noninverting input,
while the error amplifier output is applied into the inverting
input. Output switch conduction is initiated when C is
discharged to the oscillator valley voltage. As C charges to
T
a voltage that exceeds the error amplifier output, the latch
resets, terminating output transistor conduction for the
duration of the oscillator ramp–up period. This PWM/Latch
combination prevents multiple output pulses during a given
oscillator clock cycle. Figures 6 and 14 illustrate the switch
output duty cycle versus the compensation voltage.
T
shows the current source charging capacitor C
through a
from the feedback
SS
series diode. The diode disconnects C
SS
loop when the 1.0 M resistor charges it above the operating
range of Pin 5.
Current Sense
The MC34167 series utilizes cycle–by–cycle current
limiting as a means of protecting the output switch transistor
from overstress. Each on cycle is treated as a separate
situation. Current limiting is implemented by monitoring the
output switch transistor current buildup during conduction, and
upon sensing an overcurrent condition, immediately turning off
the switch for the duration of the oscillator ramp–up period.
The collector current is converted to a voltage by an
internal trimmed resistor and compared against a reference
by the Current Sense comparator. When the current limit
threshold is reached, the comparator resets the PWM latch.
The current limit threshold is typically set at 6.5 A. Figure 9
illustrates switch output current limit threshold versus
temperature.
Switch Output
The output transistor is designed to switch a maximum of
40 V, with a minimum peak collector current of 5.5 A. When
configured for step–down or voltage–inverting applications,
as in Figures 18 and 22, the inductor will forward bias the
output rectifier when the switch turns off. Rectifiers with a
high forward voltage drop or long turn on delay time should
not be used. If the emitter is allowed to go sufficiently
negative, collector current will flow, causing additional device
heating and reduced conversion efficiency. Figure 8 shows
that by clamping the emitter to 0.5 V, the collector current will
be in the range of 100 µA over temperature. A 1N5825 or
equivalent Schottky barrier rectifier is recommended to fulfill
these requirements.
Error Amplifier and Reference
Undervoltage Lockout
A high gain Error Amplifier is provided with access to the
inverting input and output. This amplifier features a typical dc
voltage gain of 80 dB, and a unity gain bandwidth of
600 kHz with 70 degrees of phase margin (Figure 3). The
noninverting input is biased to the internal 5.05 V reference
and is not pinned out. The reference has an accuracy of
± 2.0% at room temperature. To provide 5.0 V at the load, the
reference is programmed 50 mV above 5.0 V to compensate
for a 1.0% voltage drop in the cable and connector from the
An Undervoltage Lockout comparator has been
incorporated to guarantee that the integrated circuit is fully
functional before the output stage is enabled. The internal
reference voltage is monitored by the comparator which
enables the output stage when V
erratic output switching as the threshold is crossed, 0.9 V of
hysteresis is provided.
exceeds 5.9 V. To prevent
CC
6
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
Thermal Protection
Internal Thermal Shutdown circuitry is provided to protect
the integrated circuit in the event that the maximum junction
temperature is exceeded. When activated, typically at 170°C,
the latch is forced into a ‘reset’ state, disabling the output
switch. This feature is provided to prevent catastrophic failures
from accidental device overheating. It is not intended to be
used as a substitute for proper heatsinking. The MC34167
is contained in a 5–lead TO–220 type package. The tab of the
package is common with the center pin (Pin 3) and is normally
connected to ground.
DESIGN CONSIDERATIONS
Do not attempt to construct a converter on wire–wrap
or plug–in prototype boards. Special care should be taken
to separate ground paths from signal currents and ground
paths from load currents. All high current loops should be
kept as short as possible using heavy copper runs to
minimize ringing and radiated EMI. For best operation, a tight
component layout is recommended. Capacitors C , C , and
in
O
all feedback components should be placed as close to the IC
as physically possible. It is also imperative that the Schottky
diode connected to the Switch Output be located as close to
the IC as possible.
Figure 16. Over Voltage Shutdown Circuit
Figure 15. Low Power Standby Circuit
+
+
Error
Amp
Error
Amp
100
µA
100 µA
1
1
120
5
120
5
Compensation
Compensation
R
R
1
1
I = Standby Mode
V
= V
+ 0.7
Shutdown
Zener
Figure 17. Soft–Start Circuit
+
Error
Amp
100 µA
1
120
5
Compensation
D
2
R
1
D
1
V
in
C
ss
1.0 M
t
≈
35,000 C
ss
Soft–Start
7
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
Figure 18. Step–Down Converter
V
in
12 V
+
4
2
ILIMIT
+
C
330
in
Oscillator
S
Q
R
Q
1
D
1
PWM
1N5825
UVLO
L
Thermal
190 µH
Reference
EA
+
+
R
2
V
O
+
C
4700
1
6.8 k
O
5.05 V/5.0 A
C
R
F
5
F
3
0.1
68 k
R
1
Test
Conditions
= 10 V to 36 V, I = 5.0 A
Results
Line Regulation
Load Regulation
Output Ripple
Short Circuit Current
Efficiency
V
V
V
V
4.0 mV = ± 0.039%
1.0 mV = ± 0.01%
in
in
in
in
O
= 12 V, I = 0.25 A to 5.0 A
O
= 12 V, I = 5.0 A
20 mV
6.5 A
O
pp
= 12 V, R = 0.1 Ω
L
V
V
= 12 V, I = 5.0 A
78.9%
82.6%
in
in
O
= 24 V, I = 5.0 A
O
L = Coilcraft M1496–A or General Magnetics Technology GMT–0223, 42 turns of #16 AWG on
Magnetics Inc. 58350–A2 core. Heatsink = AAVID Engineering Inc. 5903B, or 5930B.
The Step–Down Converter application is shown in Figure 18. The output switch transistor Q interrupts the input voltage, generating a squarewave at the LC filter
1
O
input. The filter averages the squarewaves, producing a dc output voltage that can be set to any level between V and V by controlling the percent conduction
in ref
time of Q to that of the total oscillator cycle time. If the converter design requires an output voltage greater than 5.05 V, resistor R must be added to form a divider
1
1
network at the feedback input.
Figure 19. Step–Down Converter Printed Circuit Board and Component Layout
3.0″
V
O
–
+
V
in
+
–
+
C
F
RF
R1
+
(Bottom View)
(Top View)
8
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
Figure 20. Step–Up/Down Converter
V
12 V
in
4
+
ILIMIT
+
C
in
330
Oscillator
S
D
1
Q
Q
1
1N5825
R
2
L
PWM
UVLO
190 µH
*R
620
G
D
4
1N4148
Thermal
Q
2
MTP3055EL
Reference
EA
D
+
3
+
1N967A
D
2
1N5822
R
2
V
O
+
C
2200
1
6.8 k
O
28 V/0.9 A
C
R
F
5
F
3
R
1.5 k
0.47
4.7 k
1
*Gate resistor R , zener diode D , and diode D are required only when V is greater than 20 V.
G
3
4
in
Test
Conditions
Results
Line Regulation
Load Regulation
Output Ripple
V
V
V
V
= 10 V to 24 V, I = 0.9 A
10 mV = ± 0.017%
30 mV = ± 0.053%
in
in
in
in
O
= 12 V, I = 0.1 A to 0.9 A
O
= 12 V, I = 0.9 A
140 mV
6.0 A
O
pp
Short Circuit Current
Efficiency
= 12 V, R = 0.1 Ω
L
V
V
= 12 V, I = 0.9 A
80.1%
87.8%
in
in
O
= 24 V, I = 0.9 A
O
L = Coilcraft M1496–A or General Magnetics Technology GMT–0223, 42 turns of #16 AWG on
Magnetics Inc. 58350–A2 core.
Heatsink = AAVID Engineering Inc.
MC34167: 5903B, or 5930B
MTP3055EL: 5925B
Figure 20 shows that the MC34167 can be configured as a step–up/down converter with the addition of an external power MOSFET. Energy is stored in the
inductor during the ON time of transistors Q and Q . During the OFF time, the energy is transferred, with respect to ground, to the output filter capacitor and load.
1
2
This circuit configuration has two significant advantages over the basic step–up converter circuit. The first advantage is that output short circuit protection is
provided by the MC34167, since Q is directly in series with V and the load. Second, the output voltage can be programmed to be less than V . Notice that during
1
in
in
the OFF time, the inductor forward biases diodes D and D , transferring its energy with respect to ground rather than with respect to V . When operating with V
in in
1
2
greater than 20 V, a gate protection network is required for the MOSFET. The network consists of components R , D , and D .
G
3
4
Figure 21. Step–Up/Down Converter Printed Circuit Board and Component Layout
3.45″
D3
V
O
–
+
D2
V
in
+
–
+
C
F
RF
R1
R
G
+
(Bottom View)
(Top View)
9
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
Figure 22. Voltage–Inverting Converter
V
in
12 V
+
4
2
ILIMIT
+
C
in
330
Oscillator
S
Q
Q
1
R
L
PWM
UVLO
190 µH
D
1
1N5825
Thermal
Reference
EA
+
+
R
1
V
O
1
2.4 k
–12 V/1.7 A
+
C
4700
O
C
R
C
1
5
F
F
3
0.47
4.7 k
R
3.3 k
2
0.047
Test
Conditions
= 10 V to 24 V, I = 1.7 A
Results
Line Regulation
Load Regulation
Output Ripple
V
V
V
V
15 mV = ± 0.61%
in
in
in
in
O
= 12 V, I = 0.1 A to 1.7 A
4.0 mV = ± 0.020%
O
= 12 V, I = 1.7 A
78 mV
5.7 A
O
pp
Short Circuit Current
Efficiency
= 12 V, R = 0.1 Ω
L
V
V
= 12 V, I = 1.7 A
79.5%
86.2%
in
in
O
= 24 V, I = 1.7 A
O
L = Coilcraft M1496–A or General Magnetics Technology GMT–0223, 42 turns of #16 AWG on
Magnetics Inc. 58350–A2 core. Heatsink = AAVID Engineering Inc. 5903B, or 5930B.
Two potential problems arise when designing the standard voltage–inverting converter with the MC34167. First, the Switch Output emitter is limited to –1.5 V with
respect to the ground pin and second, the Error Amplifier’s noninverting input is internally committed to the reference and is not pinned out. Both of these problems
are resolved by connecting the IC ground pin to the converter’s negative output as shown in Figure 22. This keeps the emitter of Q positive with respect to the
1
ground pin and has the effect of reversing the Error Amplifier inputs. Note that the voltage drop across R is equal to 5.05 V when the output is in regulation.
1
Figure 23. Voltage–Inverting Converter Printed Circuit Board and Component Layout
3.0″
+
+
+
V
O
–
+
V
in
+
–
RF
C
F
+
+
+
(Bottom View)
(Top View)
10
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
Figure 24. Triple Output Converter
V
24 V
in
4
2
+
ILIMIT
+
1000
Oscillator
S
R
Q
1N5825
PWM
UVLO
MUR110
MUR110
V
O3
–12 V/200 mA
1000
1000
+
Thermal
T1
V
O2
Reference
EA
+
12 V/250 mA
+
+
6.8 k
V
O1
5.0 V/3.0 A
+
1
1000
5
3
0.1
68 k
Tests
Conditions
= 3.0 A, I = 250 mA, I = 200 mA
O3
Results
Line Regulation
Load Regulation
Output Ripple
5.0 V
12 V
–12 V
V
in
= 15 V to 30 V, I
3.0 mV = ± 0.029%
572 mV = ± 2.4%
711 mV = ± 2.9%
O1
O2
5.0 V
12 V
–12 V
V
V
V
= 24 V, I
= 24 V, I
= 24 V, I
= 30 mA to 3.0 A, I
= 250 mA, I = 200 mA
O3
1.0 mV = ± 0.009%
409 mV = ±1.5%
528 mV = ± 2.0%
in
in
in
O1
O1
O1
O2
= 100 mA to 250 mA, I
= 3.0 A, I
= 3.0 A, I
= 200 mA
O3
O2
O2
= 250 mA, I
= 75 mA to 200 mA
O3
5.0 V
12 V
–12 V
V
in
= 24 V, I
= 3.0 A, I
= 250 mA, I
= 200 mA
75 mV
20 mV
20 mV
O1
O2
O3
pp
pp
pp
Short Circuit Current
Efficiency
5.0 V
12 V
–12 V
V
= 24 V, R = 0.1 Ω
6.5 A
2.7 A
2.2 A
in
L
TOTAL
V
= 24 V, I
= 3.0 A, I
= 250 mA, I
= 200 mA
84.2%
in
O1
O2
O3
T1 = Primary: Coilcraft M1496–A or General Magnetics Technology GMT–0223, 42 turns of #16 AWG on Magnetics Inc. 58350–A2 core.
T1 = Secondary: V
T1 = Secondary: V
Heatsink = AAVID Engineering Inc. 5903B, or 5930B.
– 69 turns of #26 AWG
– 104 turns of #28 AWG
O2
O3
Multiple auxiliary outputs can easily be derived by winding secondaries on the main output inductor to form a transformer. The secondaries must be connected so
that the energy is delivered to the auxiliary outputs when the Switch Output turns off. During the OFF time, the voltage across the primary winding is regulated by
the feedback loop, yielding a constant Volts/Turn ratio. The number of turns for any given secondary voltage can be calculated by the following equation:
V
V
F(SEC)
O(SEC)
# TURNS
(SEC)
V
V
O(PRI)
F(PRI)
(PRI)
#TURNS
Note that the 12 V winding is stacked on top of the 5.0 V output. This reduces the number of secondary turns and improves lead regulation. For best auxiliary
regulation, the auxiliary outputs should be less than 33% of the total output power.
11
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
Figure 25. Negative Input/Positive Output Regulator
+
4
ILIMIT
22
0.01
1N5825
Oscillator
S
R
R
1
R
2
Q
V
O
Q
5.05
0.7
1
2
UVLO
PWM
L
V
O
MUR415
R
+ 36 V/0.3 A
1
D
1
+
Thermal
1000
R
36 k
1
MTP
Reference
EA
+
3055E
2N3906
+
Z
1
1
6.8 k
5
0.22
470 k
3
R
5.1 k
2
0.002
V
in
–12 V
1000
+
*Gate resistor R , zener diode D , and diode D are required only when V is greater than 20 V.
G
3
4
in
Test
Conditions
Results
Line Regulation
Load Regulation
Output Ripple
Efficiency
V
= –10 V to – 20 V, I = 0.3 A
266 mV = ± 0.38%
7.90 mV = ±1.1%
in
in
in
O
V
V
= –12 V, I = 0.03 A to 0.3 A
O
= –12 V, I = 0.3 A
100 mV
78.4%
O
pp
V
= –12 V, I = 0.3 A
O
in
L = General Magnetics Technology GMT–0223, 42 turns of #16 AWG on Magnetics Inc. 58350–A2
core. Heatsink = AAVID Engineering Inc. 5903B or 5930B
Figure 26. Variable Motor Speed Control with EMF Feedback Sensing
V
18 V
in
+
4
2
ILIMIT
+
1000
Oscillator
S
R
Q
UVLO
1N5825
PWM
Brush
Motor
Thermal
Reference
EA
+
+
50 k
Faster
1
5.6 k
1.0 k
47
+
5
0.1
56 k
3
Test
Conditions
Results
Low Speed Line Regulation
High Speed Line Regulation
V
= 12 V to 24 V
= 12 V to 24 V
1760 RPM ±1%
3260 RPM ± 6%
in
V
in
12
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
Figure 27. Off–Line Preconverter
0.001
T1
MBR20100CT
MC34167
Step–Down
Converter
+
+
+
+
+
+
1000
Output 1
Output 2
Output 3
0.001
0.001
1N5404
100k
RFI
Filter
115 VAC
+
220
MJE13005
MBR20100CT
0.047
1N4937
T
2
MC34167
Step–Down
Converter
0.01
50
1000
0.001
0.001
3.3
1N4003
100
+
MBR20100CT
MC34167
Step–Down
Converter
1000
0.001
T
T
T
T
T
= Core and Bobbin – Coilcraft PT3595
= Primary – 104 turns #26 AWG
= Base Drive – 3 turns #26 AWG
= Secondaries – 16 turns #16 AWG
= Total Gap – 0.002,
T
T
T
T
T
= Core – TDK T6 x 1.5 x 3 H5C2
= 14 turns center tapped #30 AWG
= Heatsink = AAVID Engineering Inc.
= MC34167 and MJE13005 – 5903B
= MBR20100CT – 5925B
1
1
1
1
1
2
2
2
2
2
The MC34167 can be used cost effectively in off–line applications even though it is limited to a maximum input voltage of 40 V. Figure 27 shows a simple and
efficient method for converting the AC line voltage down to 24 V. This preconverter has a total power rating of 125 W with a conversion efficiency of 90%.
Transformer T provides output isolation from the AC line and isolation between each of the secondaries. The circuit self–oscillates at 50 kHz and is controlled by
1
the saturation characteristics of T . Multiple MC34167 post regulators can be used to provide accurate independently regulated outputs for a distributed power
2
system.
2
Figure 28. D PAK Thermal Resistance and Maximum
Power Dissipation versus P.C.B. Copper Length
80
70
3.5
P
for T = +50°C
A
D(max)
3.0
2.5
2.0
1.5
1.0
Free Air
Mounted
Vertically
2.0 oz. Copper
L
60
50
40
30
Minimum
Size Pad
L
R
θ
JA
0
5.0
10
15
20
25
30
L, LENGTH OF COPPER (mm)
13
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
Table 1. Design Equations
Step–Down
Calculation
Step–Up/Down
Voltage–Inverting
t
t
on
off
V
out
V
V
F2
V
V
|V
V
|
V
F
sat
F1
out
V
F
V
out
in
V
V
V
V
V
in
in
satQ1
satQ2
sat
out
(Notes 1, 2)
t
t
t
t
t
t
on
off
on
off
on
off
t
on
t
on
t
off
t
on
t
on
t
off
f
1
f
1
f
1
osc
osc
osc
t
off
Duty Cycle
(Note 3)
t
f
t
f
t
f
on osc
on osc
on osc
t
t
t
t
on
off
on
off
I
I
I
1
I
1
I
L avg
out
out
out
I
2
I
L
2
L
L
I
pk(switch)
I
I
I
L avg
L avg
L avg
2
V
in
V
V
V
in
V
V
out
V
in
V
sat
L
satQ1
satQ2
sat
L
t
on
t
on
t
on
I
L
I
L
I
t
on
t
off
t
on
t
off
1
1
1
V
2
2
(ESR)
2
2
2
2
(ESR)
I
L
1
(ESR)
1
ripple(pp)
8f
C
f
C
f
C
osc o
osc o
osc o
R
R
R
R
R
R
2
1
2
1
2
1
V
out
V
ref
1
V
ref
1
V
ref
1
NOTES: 1. V
– Switch Output source saturation voltage, refer to Figure 7.
sat
2. V – Output rectifier forward voltage drop. Typical value for 1N5822 Schottky barrier rectifier is 0.35 V.
F
3. Duty cycle is calculated at the minimum operating input voltage and must not exceed the guaranteed minimum DC
specification of 0.92.
(max)
The following converter characteristics must be chosen:
V
– Desired output voltage.
– Desired output current.
out
I
out
∆I – Desired peak–to–peak inductor ripple current. For maximum output current especially when the duty cycle is greater than 0.5, it is suggested that
L
∆I be chosen minimum current limit threshold of 5.5 A. If the design goal is to use a minimum inductance value, let ∆I = 2 (I
proportionally reduce the converter’s output current capability.
). This will
L
L
L avg
V
– Desired peak–to–peak output ripple voltage. For best performance, the ripple voltage should be kept to less than 2% of V . Capacitor C should
be a low equivalent series resistance (ESR) electrolytic designed for switching regulator applications.
ripple(pp)
out
O
14
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
OUTLINE DIMENSIONS
TH SUFFIX
PLASTIC PACKAGE
CASE 314A–03
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
SEATING
PLANE
–T
–
Y14.5M, 1982.
–P
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION D DOES NOT INCLUDE
INTERCONNECT BAR (DAMBAR) PROTRUSION.
DIMENSION D INCLUDING PROTRUSION SHALL
NOT EXCEED 0.043 (1.092) MAXIMUM.
–
C
B
E
Q
OPTIONAL
CHAMFER
INCHES
MIN MAX
0.613 14.529 15.570
MILLIMETERS
MIN MAX
DIM
A
B
C
D
E
F
G
J
K
L
Q
S
0.572
0.390
0.170
0.025
0.048
0.570
A
U
0.415
0.180
0.038
0.055
9.906 10.541
F
L
4.318
0.635
1.219
4.572
0.965
1.397
K
1 2 3 4 5
0.585 14.478 14.859
1.702 BSC
0.381 0.635
0.745 18.542 18.923
0.067 BSC
0.015
0.730
0.320
0.140
0.210
0.468
0.025
G
J 5 PL
0.365
0.153
0.260
8.128
3.556
5.334
9.271
3.886
6.604
S
D 5 PL
0.014 (0.356)
U
0.505 11.888 12.827
M
M
T
P
TV SUFFIX
PLASTIC PACKAGE
CASE 314B–05
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION D DOES NOT INCLUDE
INTERCONNECT BAR (DAMBAR) PROTRUSION.
DIMENSION D INCLUDING PROTRUSION SHALL
NOT EXCEED 0.043 (1.092) MAXIMUM.
C
B
–P
–
OPTIONAL
CHAMFER
Q
E
INCHES
MIN MAX
0.613 14.529 15.570
MILLIMETERS
MIN MAX
DIM
A
B
C
D
E
A
0.572
0.390
0.170
0.025
0.048
0.850
U
0.415
0.180
0.038
0.055
9.906 10.541
L
S
V
4.318
0.635
1.219
4.572
0.965
1.397
W
1 2 3 4 5
F
K
F
0.935 21.590 23.749
0.067 BSC
0.166 BSC
1.702 BSC
4.216 BSC
G
H
J
K
L
N
Q
S
U
V
0.015
0.900
0.320
0.025
1.100 22.860 27.940
0.365
8.128 9.271
8.128 BSC
0.381
0.635
0.320 BSC
J 5 PL
0.140
0.153
0.620
3.556
3.886
G
M
0.24 (0.610)
T
H
–
0.468
–
–
15.748
0.505 11.888 12.827
0.735
0.110
D 5 PL
–
18.669
2.794
N
M
M
0.10 (0.254)
T
P
W
0.090
2.286
SEATING
PLANE
–T
–
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding
the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and
specificallydisclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters which may be provided in Motorola
datasheetsand/orspecificationscananddovaryindifferentapplicationsandactualperformancemayvaryovertime. Alloperatingparameters,including“Typicals”
must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of
others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other
applicationsintended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury
ordeathmayoccur. ShouldBuyerpurchaseoruseMotorolaproductsforanysuchunintendedorunauthorizedapplication,BuyershallindemnifyandholdMotorola
and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees
arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that
Motorola was negligent regarding the design or manufacture of the part. Motorola and
Opportunity/Affirmative Action Employer.
are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal
15
MOTOROLA ANALOG IC DEVICE DATA
MC34167 MC33167
OUTLINE DIMENSIONS
T SUFFIX
PLASTIC PACKAGE
CASE 314D–03
SEATING
PLANE
–T
–
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
C
Y14.5M, 1982.
–Q
–
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION D DOES NOT INCLUDE
INTERCONNECT BAR (DAMBAR) PROTRUSION.
DIMENSION D INCLUDING PROTRUSION SHALL
NOT EXCEED 10.92 (0.043) MAXIMUM.
B
E
U
INCHES
MIN MAX
0.613 14.529 15.570
MILLIMETERS
MIN MAX
A
S
DIM
A
B
C
D
E
G
H
J
K
L
Q
U
S
0.572
0.390
0.170
0.025
0.048
L
0.415
0.180
0.038
0.055
9.906 10.541
1 2 3
4 5
4.318
0.635
1.219
4.572
0.965
1.397
K
0.067 BSC
1.702 BSC
0.087
0.015
1.020
0.320
0.140
0.105
0.543
0.112
0.025
2.210
0.381
2.845
0.635
1.065 25.908 27.051
0.365
0.153
0.117
8.128
3.556
2.667
9.271
3.886
2.972
J
G
0.582 13.792 14.783
H
D 5 PL
M
M
0.356 (0.014)
T
Q
D2T SUFFIX
PLASTIC PACKAGE
CASE 936A–02
2
(D PAK)
OPTIONAL
CHAMFER
NOTES:
TERMINAL 6
–T
–
1
DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
A
U
E
2
3
CONTROLLING DIMENSION: INCH.
TAB CONTOUR OPTIONAL WITHIN DIMENSIONS
A AND K.
4
5
DIMENSIONS U AND V ESTABLISH A MINIMUM
MOUNTING SURFACE FOR TERMINAL 6.
DIMENSIONS A AND B DO NOT INCLUDE MOLD
FLASH OR GATE PROTRUSIONS. MOLD FLASH
AND GATE PROTRUSIONS NOT TO EXCEED
0.025 (0.635) MAXIMUM.
S
K
V
B
H
INCHES
MILLIMETERS
MIN MAX
9.804 10.236
1
2
3
4
5
DIM
A
B
C
D
E
MIN
MAX
0.403
0.368
0.180
0.036
0.055
0.386
0.356
0.170
0.026
0.045
M
9.042
4.318
0.660
1.143
9.347
4.572
0.914
1.397
L
P
N
G
H
K
L
M
N
P
R
S
U
V
0.067 BSC
0.539
0.050 REF
1.702 BSC
0.579 13.691 14.707
1.270 REF
D
R
M
0.010 (0.254)
T
0.000
0.088
0.018
0.058
5
0.010
0.102
0.026
0.078
0.000
0.254
2.591
0.660
1.981
G
2.235
0.457
1.473
5
REF
REF
0.116 REF
0.200 MIN
0.250 MIN
2.946 REF
5.080 MIN
6.350 MIN
C
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MC34167/D
◊
相关型号：
MC34167TVG
8A SWITCHING REGULATOR, 81kHz SWITCHING FREQ-MAX, PZFM5, LEAD FREE, TO-220, 5 PIN
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