MOTOROLA MC33261D

Order this document by MC34261/D
The MC34261/MC33261 are active power factor controllers specifically
designed for use as a preconverter in electronic ballast and in off–line power
converter applications. These integrated circuits feature an internal startup
timer, a one quadrant multiplier for near unity power factor, zero current
detector to ensure critical conduction operation, high gain error amplifier,
trimmed internal bandgap reference, current sensing comparator, and a
totem pole output ideally suited for driving a power MOSFET.
Also included are protective features consisting of input undervoltage
lockout with hysteresis, cycle–by–cycle current limiting, and a latch for single
pulse metering. These devices are available in dual–in–line and surface
mount plastic packages.
• Internal Startup Timer
•
•
•
•
•
•
•
•
POWER FACTOR
CONTROLLERS
SEMICONDUCTOR
TECHNICAL DATA
P SUFFIX
PLASTIC PACKAGE
CASE 626
One Quadrant Multiplier
Zero Current Detector
8
Trimmed 2% Internal Bandgap Reference
1
Totem Pole Output
Undervoltage Lockout with Hysteresis
Low Startup and Operating Current
D SUFFIX
PLASTIC PACKAGE
CASE 751
(SO–8)
Pinout Equivalent to the SG3561
Functional Equivalent to the TDA4817
8
1
PIN CONNECTIONS
Simplified Block Diagram
Zero Current Detector
5
2.5V
Reference
Undervoltage
Lockout
Zero Current
Detect Input
Voltage Feedback
Input
Compensation
Multiplier Input
Current Sense
Input
8 VCC
7 Drive Output
6 Gnd
5 Zero Current
Detect Input
1
2
3
4
(Top View)
VCC
8
Drive Output
7
Multiplier,
Latch,
PWM,
Timer,
&
Logic
Current Sense
Input
4
ORDERING INFORMATION
Error Amp
Multiplier
Input 3
6
Vref
Voltage
Feedback
1 Input
Multiplier
Gnd
Device
Compensation
2
MC34261D
MC34261P
MC33261D
MC33261P
Operating
Temperature Range
TA = 0° to +70°C
TA = – 40° to +85°C
 Motorola, Inc. 1996
MOTOROLA ANALOG IC DEVICE DATA
Package
SO–8
Plastic DIP
SO–8
Plastic DIP
Rev 1
1
MC34261 MC33261
MAXIMUM RATINGS
Rating
Symbol
Value
Unit
(ICC + IZ)
30
mA
Output Current, Source or Sink (Note 1)
IO
500
mA
Current Sense, Multiplier, and Voltage Feedback Inputs
Vin
–1.0 to 10
V
Zero Current Detect Input
High State Forward Current
Low State Reverse Current
Iin
Total Power Supply and Zener Current
Power Dissipation and Thermal Characteristics
P Suffix, Plastic Package Case 626
Maximum Power Dissipation @ TA = 70°C
Thermal Resistance, Junction–to–Air
D Suffix, Plastic Package Case 626
Maximum Power Dissipation @ TA = 70°C
Thermal Resistance, Junction–to–Air
mA
50
–10
PD
RθJA
800
100
mW
°C/W
PD
RθJA
450
178
mW
°C/W
Operating Junction Temperature
TJ
+150
°C
Operating Ambient Temperature (Note 3)
MC34261
MC33261
TA
Storage Temperature
°C
0 to +70
–40 to +85
Tstg
–55 to +150
°C
ELECTRICAL CHARACTERISTICS (VCC = 12 V, for typical values TA = 25°C, for min/max values TA is the operating ambient
temperature range that applies [Note 3], unless otherwise noted.)
Characteristic
Symbol
Min
Typ
Max
2.465
2.44
2.5
2.535
2.54
Unit
ERROR AMPLIFIER
Voltage Feedback Input Threshold
TA = 25°C
TA = Tlow to Thigh (VCC = 12 V to 28 V)
Line Regulation (VCC = 12 V to 28 V, TA = 25°C)
VFB
V
Regline
–
1.0
10
mV
IIB
–
–0.3
–1.0
µA
Open Loop Voltage Gain
AVOL
65
85
–
dB
Gain Bandwidth Product (TA = 25°C)
GBW
0.7
1.0
–
MHz
ISource
0.25
0.5
0.75
mA
VOH
VOL
5.0
–
5.7
2.1
–
2.44
Dynamic Input Voltage Range
Multiplier Input (Pin 3)
Compensation (Pin 2)
VPin 3
VPin 2
0 to 2.5
VFB to
(VFB + 1.0)
0 to 3.5
VFB to
(VFB + 1.5)
–
–
Input Bias Current (VFB = 0 V)
IIB
–
–0.3
–1.0
µA
Multiplier Gain (VPin 3 = 0.5 V, VPin 2 = VFB + 1.0 V) (Note 2)
K
0.4
0.62
0.8
1/V
Input Threshold Voltage (Vin Increasing)
Vth
1.3
1.6
1.8
V
Hysteresis (Vin Decreasing)
VH
40
110
200
mV
Input Clamp Voltage
High State (IDET = 3.0 mA)
Low State (IDET = –3.0 mA)
VIH
VIL
6.1
0.3
6.7
0.7
–
1.0
Input Bias Current (VFB = 0 V)
Output Source Current (VO = 4.0 V, VFB = 2.3 V)
Output Voltage Swing
High State (ISource = 0.2 mA, VFB = 2.3 V)
Low State (ISink = 0.4 mA, VFB = 2.7 V)
V
MULTIPLIER
V
ZERO CURRENT DETECTOR
V
NOTES: 1. Maximum package power dissipation limits must be observed.
Pin 4 Threshold Voltage
2. K =
VPin 3(VPin 2 – VFB)
3. Tlow = –40°C for MC34261
Thigh = +70°C for MC34261
3. Tlow = –40°C for MC33261
Thigh = +85°C for MC33261
2
MOTOROLA ANALOG IC DEVICE DATA
MC34261 MC33261
ELECTRICAL CHARACTERISTICS (VCC = 12 V, for typical values TA = 25°C, for min/max values TA is the operating ambient
temperature range that applies [Note 3], unless otherwise noted.)
Characteristic
Symbol
Min
Typ
Max
Unit
Input Bias Current (VPin 4 = 0 V)
IIB
–
–0.5
–2.0
µA
Input Offset Voltage (VPin 2 = 1.1 V, VPin 3 = 0 V)
VIO
–
3.5
15
mV
tPHL (in/out)
–
200
400
ns
VOL
–
1.8
9.8
7.8
0.3
2.4
10.3
8.3
0.8
3.3
–
8.8
14
16
18
CURRENT SENSE COMPARATOR
Delay to Output
DRIVE OUTPUT
Output Voltage (VCC = 12 V)
Low State (ISink = 20 mA)
Low State (ISink = 200 mA)
High State (ISource = 20 mA)
High State (ISource = 200 mA)
V
VOH
Output Voltage (VCC = 30 V)
High State (ISource = 20 mA, CL = 15 pF)
VO(max)
V
Output Voltage Rise Time (CL = 1.0 nF)
tr
–
50
120
ns
Output Voltage Fall Time (CL = 1.0 nF)
tf
–
50
120
ns
VOH(UVLO)
–
0.2
0.8
V
tDLY
150
400
–
µs
Vth
9.2
10.0
10.8
V
VShutdown
7.0
8.0
9.0
V
VH
1.75
2.0
2.5
V
–
–
–
0.3
7.1
9.0
0.5
12
20
30
36
–
Output Voltage with UVLO Activated (VCC = 7.0 V, ISink = 1.0 mA)
RESTART TIMER
Restart Time Delay
UNDERVOLTAGE LOCKOUT
Startup Threshold (VCC Increasing)
Minimum Operating Voltage After Turn–On (VCC Decreasing)
Hysteresis
TOTAL DEVICE
Power Supply Current
Startup (VCC = 7.0 V)
Operating
Dynamic Operating (50 kHz, CL = 1.0 nF)
ICC
Power Supply Zener Voltage
VZ
mA
V
NOTES: 1. Maximum package power dissipation limits must be observed.
Pin 4 Threshold Voltage
2. K =
VPin 3(VPin 2 – VFB)
Thigh = +70°C for MC34261
Thigh = +85°C for MC33261
Figure 1. Current Sense Input Threshold
versus Multiplier Input
3.0
2.5
2.0
1.5
1.0
0.5
0
See Figure 2
–0.5
–0.5
0
0.5
1.0
1.5
2.0
2.5
3.0
VM, MULTIPLIER INPUT VOLTAGE (V)
MOTOROLA ANALOG IC DEVICE DATA
3.5
4.0
V CS , CURRENT SENSE THRESHOLD VOLTAGE (V)
V CS , CURRENT SENSE THRESHOLD VOLTAGE (V)
3. Tlow = –40°C for MC34261
3. Tlow = –40°C for MC33261
Figure 2. Current Sense Input Threshold
versus Multiplier Input
0.16
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0
–0.02
–0.12
–0.08
–0.04
0
0.04
0.08
0.12
VM, MULTIPLIER INPUT VOLTAGE (V)
3
Figure 3. Voltage Feedback Input Threshold
Change versus Temperature
Figure 4. Error Amp Open Loop Gain and
Phase versus Frequency
100
A VOL, OPEN LOOP VOLTAGE GAIN (dB)
+4.0
VCC = 12 V
Pins 1 to 2
0
–4.0
–8.0
–12
–16
–55
–25
0
25
50
75
100
0
80
Gain
60
40
90
Phase
20
150
100
1.0 k
VCC = 12 V
AV = –1.0
TA = 25°C
1.0 M
180
10 M
VCC = 12 V
AV = –1.0
TA = 25°C
200 mV/DIV
20 mV/DIV
3.0 V
2.5 V
2.0 V
2.45 V
0.5 µs/DIV
1.0 µs/DIV
Figure 7. Error Amp Output Saturation
versus Sink Current
Figure 8. Restart Time Delay versus Temperature
5.0
525
VCC = 12 V
VFB = 2.7 V
4.0 TA = 25°C
t DLY , RESTART TIME DELAY ( µs)
Vsat , OUTPUT SATURATION VOLTAGE (V)
100 k
Figure 6. Error Amp Large Signal
Transient Response
2.5 V
3.0
2.0
1.0
4
10 k
f, FREQUENCY (Hz)
Figure 5. Error Amp Small Signal
Transient Response
0
120
0
TA, AMBIENT TEMPERATURE (°C)
2.55 V
30
60
–20
10
125
VCC = 12 V
VO = 3.0 V to 3.5 V
RL = 100 k
TA = 25°C
φ, EXCESS PHASE ( ° C)
∆ VFB , VOLTAGE FEEDBACK THRESHOLD CHANGE (mV)
MC34261 MC33261
0
0.5
1.0
1.5
ISink, OUTPUT SINK CURRENT (mA)
2.0
475
425
375
VCC = 12 V
325
275
–55
–25
0
25
50
75
TA, AMBIENT TEMPERATURE (°C)
100
125
MOTOROLA ANALOG IC DEVICE DATA
MC34261 MC33261
Figure 10. Output Saturation Voltage
versus Load Current
0
40
Vsat , OUTPUT SATURATION VOLTAGE (V)
VCC
–2.0
20
VCC = 12 V
–6.0
Lower Threshold
(Vin Decreasing)
–25
0
25
50
75
TA, AMBIENT TEMPERATURE (°C)
100
Sink Saturation
(Load to VCC)
2.0
Gnd
0
125
0
VO , OUTPUT VOLTAGE
Figure 11. Drive Output Waveform
VCC = 12 V
CL = 1.0 nF
TA = 25°C
10
%
100 ns/DIV
320
Figure 12. Drive Output Cross Conduction
VCC = 12 V
CL = 15 pF
TA = 25°C
100 ns/DIV
Figure 14. Undervoltage Lockout Thresholds
versus Temperature
Figure 13. Supply Current versus Supply Voltage
16
12
11
VCC , SUPPLY VOLTAGE (V)
I CC , SUPPLY CURRENT (mA)
80
160
240
IO, OUTPUT LOAD CURRENT (mA)
I CC , SUPPLY CURRENT
90
%
4.0
5.0 V/DIV
–20
–40
–55
Source Saturation
(Load to Ground)
–4.0
Upper Threshold
(Vin Increasing)
0
VCC = 12 V
80 µs Pulsed Load
120 Hz Rate
100 mA/DIV
∆ V th , THRESHOLD VOLTAGE CHANGE (mV)
Figure 9. Zero Current Detector Input Threshold
Voltage Change versus Temperature
12
8.0
VFB = 0 V
Current Sense = 0 V
Multiplier = 0 V
CL = 1.0 nF
f = 50 kHz
TA = 25°C
4.0
0
0
10
20
VCC, SUPPLY VOLTAGE (V)
MOTOROLA ANALOG IC DEVICE DATA
30
Startup Threshold
(VCC Increasing)
10
9.0
8.0
Minimum Operating Threshold
(VCC Decreasing)
7.0
40
6.0
–55
–25
0
25
50
75
TA, AMBIENT TEMPERATURE (°C)
100
125
5
MC34261 MC33261
FUNCTIONAL DESCRIPTION
Introduction
Most electronic ballasts and switching power supplies use
a bridge rectifier and a filter capacitor to derive raw dc voltage
from the utility ac line. This simple rectifying circuit draws
power from the line when the instantaneous ac voltage
exceeds the capacitor’s voltage. This occurs near the line
voltage peak and results in a high charge current spike.
Since power is only taken near the line voltage peaks, the
resulting spikes of current are extremely nonsinusoidal with a
high content of harmonics. This results in a poor power factor
condition where the apparent input power is much higher
than the real power.
The MC34261, MC33261 are high performance, critical
conduction, current mode power factor controllers
specifically designed for use in off–line active preconverters.
These devices provide the necessary features required to
significantly enhance poor power factor loads by keeping the
ac line current sinusoidal and in phase with the line voltage.
With proper control of the preconverter, almost any complex
load can be made to appear resistive to the ac line, thus
significantly reducing the harmonic current content.
Operating Description
The MC34261, MC33261 contains many of the building
blocks and protection features that are employed in modern
high performance current mode power supply controllers.
There are, however, two areas where there is a major
difference when compared to popular devices such as the
UC3842 series. Referring to the block diagram in Figure 15,
note that a multiplier has been added to the current sense
loop and that this device does not contain an oscillator. A
description of each of the functional blocks is given below.
Error Amplifier
A fully compensated Error Amplifier with access to the
inverting input and output is provided. It features a typical dc
voltage gain of 85 dB, and a unity gain bandwidth of 1.0 MHz
with 58° of phase margin (Figure 4). The noninverting input is
internally biased at 2.5 V ±2.0% and is not pinned out. The
output voltage of the power factor converter is typically
divided down and monitored by the inverting input. The
maximum input bias current is –1.0 µA which can cause an
output voltage error that is equal to the product of the input
bias current and the value of the upper divider resistor R2.
The Error Amp Output is internally connected to the Multiplier
and is pinned out (Pin 2) for external loop compensation.
Typically, the bandwidth is set below 20 Hz, so that the Error
Amp output voltage is relatively constant over a given ac line
cycle. The output stage consists of a 500 µA current source
pull–up with a Darlington transistor pull–down. It is capable of
swinging from 2.1 V to 5.7 V, assuring that the Multiplier can
be driven over its entire dynamic range.
Multiplier
A single quadrant, two input multiplier is the critical
element that enables this device to control power factor. The
ac haversines are monitored at Pin 3 with respect to ground
while the Error Amp output at Pin 2 is monitored with respect
6
to the Voltage Feedback Input threshold. A graph of the
Multiplier transfer curve is shown in Figure 1. Note that both
inputs are extremely linear over a wide dynamic range, 0 V to
3.2 V for the Multiplier input (Pin 3), and 2.5 V to 4.0 V for the
Error Amp output (Pin 2). The Multiplier output controls the
Current Sense Comparator threshold (Pin 4) as the ac
voltage traverses sinusoidally from zero to peak line. This
has the effect of forcing the MOSFET peak current to track
the input line voltage, thus making the preconverter load
appear to be resistive.
Pin 4 Threshold ≈ 0.62(VPin 2 – VFB)VPin 3
Zero Current Detector
The MC34261 operates as a critical conduction current
mode controller, whereby output switch conduction is
initiated by the Zero Current Detector and terminated when
the peak inductor current reaches the threshold level
established by the Multiplier output. The Zero Current
Detector initiates the next on–time by setting the RS Latch at
the instant the inductor current reaches zero. This critical
conduction mode of operation has two significant benefits.
First, since the MOSFET cannot turn on until the inductor
current reaches zero, the output rectifier’s reverse recovery
time becomes less critical allowing the use of an inexpensive
rectifier. Second, since there are no deadtime gaps between
cycles, the ac line current is continuous thus limiting the peak
switch to twice the average input current.
The Zero Current Detector indirectly senses the inductor
current by monitoring when the auxiliary winding voltage falls
below 1.6 V. To prevent false tripping, 110 mV of hysteresis is
provided. The Zero Current Detector input is internally
protected by two clamps. The upper 6.7 V clamp prevents
input overvoltage breakdown while the lower 0.7 V clamp
prevents substrate injection. Device destruction can result if
this input is shorted to ground. An external resistor must be
used in series with the auxiliary winding to limit the current
through the clamps.
Current Sense Comparator and RS Latch
The Current Sense Comparator RS Latch configuration
ensures that only a single pulse appears at the Drive Output
during a given cycle. The inductor current is converted to a
voltage by inserting a ground referenced sense resistor R9 in
series with the source of output switch Q1. This voltage is
monitored by the Current Sense Input and compared to the
Multiplier output voltage. The peak inductor current is
controlled by the threshold voltage of Pin 4 where:
Ipk =
Pin 4 Threshold
R9
With the component values shown in Figure 16, the
Current Sense Comparator threshold, at the peak of the
haversine varies from 1.1 V at 90 Vac to 100 mV at 268 Vac.
The Current Sense Input to Drive Output propagation delay is
typically 200 ns.
MOTOROLA ANALOG IC DEVICE DATA
MC34261 MC33261
Timer
A watchdog timer function was added to the IC to eliminate
the need for an external oscillator when used in stand alone
applications. The Timer provides a means to automatically
start or restart the preconverter if the Drive Output has been
off for more than 400 µs after the inductor current reaches
zero.
Undervoltage Lockout
An Undervoltage Lockout comparator guarantees that the
IC is fully functional before enabling the output stage. The
positive power supply terminal (VCC) is monitored by the
UVLO comparator with the upper threshold set at 10 V and
the lower threshold at 8.0 V (Figure 14). In the standby mode,
with VCC at 7.0 V, the required supply current is less than
0.5 mA (Figure 13). This hysteresis and low startup current
allow the implementation of efficient bootstrap startup
techniques, making these devices ideally suited for wide
input range off line preconverter applications. An internal 36
V clamp has been added from VCC to ground to protect the IC
and capacitor C5 from an overvoltage condition. This feature
is desirable if external circuitry is used to delay the startup of
the preconverter.
Output
The MC34261/MC33261 contain a single totem pole
output stage specifically designed for direct drive of power
MOSFETs. The Drive Output is capable of up to ±500 mA
peak current with a typical rise and fall time of 50 ns with a
1.0 nF load. Additional internal circuitry has been added to
keep the Drive Output in a sinking mode whenever the
Undervoltage Lockout is active. This characteristic
eliminates the need for an external gate pull–down resistor.
The totem pole output has been optimized to minimize cross
conduction current during high speed operation. The addition
of two 10 Ω resistors, one in series with the source output
transistor and one in series with the sink output transistor,
reduces the cross conduction current, as shown in Figure 12.
A 16 V clamp has been incorporated into the output stage to
limit the high state VOH. This prevents rupture of the
MOSFET gate when VCC exceeds 20 V.
Table 1. Design Equations
Notes
Calculation
Calculate the maximum required output power.
Required Converter Output Power
Calculated at the minimum required ac line for
regulation. Let the efficiency n = 0.95.
Peak Inductor Current
Formula
PO = VO IO
Let the switching cycle t = 20 µs.
Inductance
2 2 PO
ηVac(LL)
IL(pk) =
ǒ VO
2t
2
L =
– VacǓ Vac2
VO Vac(LL) IL(pk)
In theory the on–time ton is constant. In practice ton
tends to increase at the ac line zero crossings due to
the charge on capacitor C6.
The off–time toff is greatest at peak ac line and
approaches zero at the ac line zero crossings.
Theta (θ) represents the angle of
the ac line voltage.
Switch Off–Time
2 PO L
ton =
Switch On–Time
η Vac2
ton
toff =
VO
2 Vac Sin θ
The minimum switching frequency occurs at peak ac
line and increases as toff decreases.
Switching Frequency
f=
Set the current sense threshold VCS to 1.0 V for
universal input (85 Vac to 265 Vac) operation and
to 0.5 V for fixed input (92 Vac to 138 Vac, or
184 to 276 Vac) operation.
Peak Switch Current
R9 =
Set the multiplier input voltage VM to 3.0 V at high
line. Empirically adjust VM for the lowest distortion
over the ac line range while guaranteeing startup at
minimum line.
Multiplier Input Voltage
The IIB R1 error term can be minimized with a divider
current in excess of 100 µA.
The bandwidth is typically set to 20 Hz for minimum
output ripple over the ac line haversine.
Converter Output Voltage
1
ton + toff
VM =
ǒ
VO = Vref
ǒ
VCS
IL(pk)
Vac
2
R7
+ 1Ǔ
R3
R2
+ 1 Ǔ – IIB R2
R1
1
BW =
Error Amplifier Bandwidth
–1
2π
R1 R2
R1 + R 2
C1
The following converter characteristics must be chosen:
Vac – AC RMS line voltage
VO – Desired output voltage
IO – Desired output current
Vac(LL) – AC RMS low line voltage
MOTOROLA ANALOG IC DEVICE DATA
7
MC34261 MC33261
Figure 15. 80 W Power Factor Controller
C6
1
D2
92 to RFI
138 Vac Filter
100k
R8
8
D4
D1
Zero Current
Detector
D3
1.2V
+
+
22k
R5
10V
MUR130
D5
RS
Latch
VO
+
Drive
Output
10
MTP
8N50E
Q1
10
7
R6
10
+ Error Amp
Vref
0.5mA
230V/0.35A
100
C4
1.0M
R2
330 R4
4
Current Sense
Comparator
T
16V
Delay
7.5k
R3
100
C5
UVLO
Timer R
0.01
C2
5
6.7V
1.6V
2.5V
Reference
2.2M
R7
+
+ 36V
+
1N4934
D6
0.1
R9
1.0nF
C3
Multiplier
3
11k
R1
1
2
6
0.68
C1
Power Factor Controller Test Data
AC Line Input
DC Output
Current Harmonic Distortion (%)
Vrms
Pin
PF
THD
2
3
5
7
VO(pp)
VO
IO
PO
n(%)
90
85.6
–0.998
2.4
0.11
0.52
1.3
0.67
10.0
230
0.350
80.5
94.0
100
85.1
–0.997
5.0
0.13
1.7
2.4
1.4
10.1
230
0.350
80.5
94.6
110
84.8
–0.997
5.3
0.12
2.5
2.6
1.5
10.2
230
0.350
80.5
94.9
120
84.5
–0.997
5.8
0.12
3.2
2.7
1.4
10.2
230
0.350
80.5
95.3
130
84.2
–0.996
6.6
0.12
4.0
2.8
1.5
10.2
230
0.350
80.5
95.6
138
84.1
–0.995
7.2
0.13
4.5
3.0
1.6
10.2
230
0.350
80.5
95.7
This data was taken with the test set–up shown in Figure 17.
T = Coilcraft N2881–A
Primary: 62 turns of # 22 AWG
Secondary: 5 turns of # 22 AWG
Core: Coilcraft PT2510, EE 25
Gap: 0.072″ total for a primary inductance of 320 µH
Heatsink = AAVID Engineering Inc. 5903B, or 5930B
8
MOTOROLA ANALOG IC DEVICE DATA
MC34261 MC33261
Figure 16. 175 W Universal Input Power Factor Controller
C6
1
D2
85 to 265 RFI
Vac
Filter
100k
R8
8
D4
D1
Zero Current
Detector
D3
1.2V
+
+
T
10V
MUR460
D5
+
16V
Drive
Output
Delay
RS
Latch
12k
R3
22k
R5
UVLO
Timer R
0.01
C2
100
C5
5
6.7V
1.6V
2.5V
Reference
1.3M
R7
+
+ 36V
+
1N4934
D6
10
R6
10
1.6M
R2
330 R4
4
Current Sense
Comparator
MTW
14N50E
Q1
10
7
+ Error Amp
Vref
0.5mA
VO
400V/0.44A
180
C4
0.1
R9
1.0nF
C3
Multiplier
3
10k
R1
1
2
6
0.68
C1
Power Factor Controller Test Data
AC Line Input
DC Output
Current Harmonic Distortion (%)
Vrms
Pin
PF
THD
2
3
5
7
VO(pp)
VO
IO
PO
n(%)
90
187.5
–0.998
2.0
0.10
0.98
0.90
0.78
8.0
400.7
0.436
174.7
93.2
120
184.6
–0.997
1.8
0.09
1.3
1.3
0.93
8.0
400.7
0.436
174.7
94.6
138
183.6
–0.997
2.3
0.05
1.6
1.5
1.0
8.0
400.7
0.436
174.7
95.2
180
181.0
–0.995
4.3
0.16
2.5
2.0
1.2
8.0
400.6
0.436
174.7
95.6
240
179.3
–0.993
6.0
0.08
3.7
2.7
1.4
8.0
400.6
0.436
174.7
97.4
268
178.6
–0.992
6.7
0.16
2.8
3.7
1.7
8.0
400.6
0.436
174.7
97.8
This data was taken with the test set–up shown in Figure 17.
T = Coilcraft N2880–A
Primary: 78 turns of # 16 AWG
Secondary: 6 turns of # 18 AWG
Core: Coilcraft PT4215, EE 42–15
Gap: 0.104″ total for a primary inductance of 870 µH
Heatsink = AAVID Engineering Inc. 5903B
MOTOROLA ANALOG IC DEVICE DATA
9
MC34261 MC33261
Figure 17. Power Factor Test Set–Up
Line
115 Vac
Input
2X Step–Up
Isolation
Transformer
RFI Filter
HI
AC POWER ANALYZER
PM 1000
W
Autoformer
0
I
Neutral
Vcf
O
VA
1
PF Vrms Arms
2
3
A
T
0.005
1.0
0.1
V
5
0 to 270 Vac
Output Power Factor
Controller Circuit
0.005
Acf Ainst FREQ HARM
LO
7
HI
9
11
LO
13
Voltech
Earth
An RFI filter is required for best performance when connecting the preconverter directly to the AC line. Commercially available two stage filters
such as the Delta Electronics 03DPCG5 work excellent. The simple single stage test filter shown above can easily be constructed with a common
mode transformer. Transformer (T) is a Coilcraft CMT3–28–2 with 28 mH minimum inductance and a 2.0 A maximum current rating.
Figure 18. Soft–Start Circuit
+
Figure 19. Error Amp Compensation
To VO
0.5 mA
10µA
1
1
2
R1
2
6
C
+
R2
Error Amp
+
1.0M
To VCC
C1
tSoft–Start ≈ 9000C in µF
Startup overshoot can be eliminated with the
addition of a Soft–Start circuit.
10
MOTOROLA ANALOG IC DEVICE DATA
MC34261 MC33261
Figure 20. Printed Circuit Board and Component Layout
(Circuits of Figures 15 and 16)
MOTOROLA ANALOG IC DEVICE DATA
11
MC34261 MC33261
OUTLINE DIMENSIONS
8
P SUFFIX
PLASTIC PACKAGE
CASE 626–05
ISSUE K
5
NOTES:
1. DIMENSION L TO CENTER OF LEAD WHEN
FORMED PARALLEL.
2. PACKAGE CONTOUR OPTIONAL (ROUND OR
SQUARE CORNERS).
3. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
–B–
1
4
F
DIM
A
B
C
D
F
G
H
J
K
L
M
N
–A–
NOTE 2
L
C
J
–T–
N
SEATING
PLANE
D
M
K
MILLIMETERS
MIN
MAX
9.40
10.16
6.10
6.60
3.94
4.45
0.38
0.51
1.02
1.78
2.54 BSC
0.76
1.27
0.20
0.30
2.92
3.43
7.62 BSC
–––
10_
0.76
1.01
INCHES
MIN
MAX
0.370
0.400
0.240
0.260
0.155
0.175
0.015
0.020
0.040
0.070
0.100 BSC
0.030
0.050
0.008
0.012
0.115
0.135
0.300 BSC
–––
10_
0.030
0.040
G
H
0.13 (0.005)
T A
M
B
M
D SUFFIX
PLASTIC PACKAGE
CASE 751–05
(SO–8)
ISSUE N
–A–
8
M
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSIONS A AND B DO NOT INCLUDE
MOLD PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.
5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.127 (0.005) TOTAL
IN EXCESS OF THE D DIMENSION AT
MAXIMUM MATERIAL CONDITION.
5
–B–
1
4X
P
0.25 (0.010)
4
M
B
M
G
R
C
–T–
8X
K
D
0.25 (0.010)
M
T B
SEATING
PLANE
S
A
M_
S
X 45 _
F
J
DIM
A
B
C
D
F
G
J
K
M
P
R
MILLIMETERS
MIN
MAX
4.80
5.00
3.80
4.00
1.35
1.75
0.35
0.49
0.40
1.25
1.27 BSC
0.18
0.25
0.10
0.25
0_
7_
5.80
6.20
0.25
0.50
INCHES
MIN
MAX
0.189
0.196
0.150
0.157
0.054
0.068
0.014
0.019
0.016
0.049
0.050 BSC
0.007
0.009
0.004
0.009
0_
7_
0.229
0.244
0.010
0.019
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
specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters which may be provided in Motorola
data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, 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
applications intended 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
or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola
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
are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal
Opportunity/Affirmative Action Employer.
Mfax is a trademark of Motorola, Inc.
How to reach us:
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INTERNET: http://motorola.com/sps
12
◊
MC34261/D
MOTOROLA ANALOG IC DEVICE
DATA