TEMIC U211B3, U211B2 Datasheet

U211B2/ B3

Phase Control Circuit - General Purpose Feedback

Description

The integrated circuit U211B2/ B3 is designed as a phase
control circuit in bipolar technology with an internal fre­quency-voltage converter. Furthermore, it has an internal
control amplifier which means it can be used for speed­regulated motor applications.

Features

D

Internal frequency-to-voltage converter

D

Externally-controlled integrated amplifier

D

Overload limitation with a “fold back” characteristic

D

Optimized soft-start function

D

Tacho monitoring for shorted and open loop

D

Automatic retriggering switchable

It has an integrated load limitation, tacho monitoring and
soft-start functions, etc. to realize sophisticated motor
control systems.

D

Triggering pulse typ. 155 mA

D

Voltage and current synchronization

D

Internal supply-voltage monitoring

D

Temperature reference source

D

Current requirement ≤ 3 mA

Package: DIP18 - U211B2,

SO16 - U211B3

11(10)

10(9)

14(13)

15(14)

17(16) 1(1)

Voltage / Current

detector

Control
amplifier

+

–

Load limitation

speed / time

controlled

controlled

current sink

5*)

Automatic
retriggering

Phase

control unit

ö

= f (V12)

Soft start

–V

Ref

12(11) 13(12) 9(8) 8(7)

Frequency-

to-voltage

converter

Output

pulse

Supply
voltage

limitation

Reference

voltage

Voltage

monitoring

Pulse-blocking

tacho

monitoring

4(4)

6(5)

7(6)

3(3)

2(2)

16(15)

18*)

95 10360

–V

S

GND

TELEFUNKEN Semiconductors

Rev . A1, 29-May-96

Figure 1. Block diagram (Pins in brackets refer to SO16)

*) Pins 5 and 18 connected internally

1 (20)

U211B2/ B3

L

M

1

D

W

18 k

1N4007

1

R

2 W

R

R

4

3

W

470 k

W

220 k

=

M

V

TIC

226

12

R

4

5

17 1

Set speed

voltage

230 V ~

8

R

W

W

1 M

180

2

R

6

pulse

Output

Automatic

retriggering

detector

Control

amplifier

Voltage / Current

11

W

19

R

100 k

10

C

W

1 W

33 m

3.3 nF

C

7

–

+

10

F

m

2.2 /16V

N

F

m

22

C

S

2

–V

3

Supply

voltage

Phase

control unit

F

m

25 V

2.2

1

C

GND

2

limitation

)

12

= f (V

ö

10

R

11

16

voltage

Voltage

Reference

controlled

speed / time

Load limitation

14

W

W

1 k

1 M

monitoring

15

9

R

C

tacho

Pulse blocking

to voltage

Frequency

Soft start

controlled

current sink

F

m

9

4.7 /16V

18

monitoring

converter

Ref

–V

12 13 9 8

95 10361

220 nF

11

R

Speed sensor

4

C

W

R

1 k

5

F

1 nF

C

m

16 V

2.2

3

8

C

C

220 nF

7

R

7

F

m

10 /16V

W

2 M

6

R

6

C

W

22 k

W

100 k

100 nF

C

voltage

Actual speed

5

2 (20)

R

31

W

100 k

W

13

R

47 k

W

14

R

56 k

Figure 2. Speed control, automatic retriggering, load limiting, soft start

TELEFUNKEN Semiconductors

Rev . A1, 29-May-96

Description

Mains Supply

The U211B2 is fitted with voltage limiting and can
therefore be supplied directly from the mains. The supply

voltage between Pin 2 (+ pol/ă) and Pin 3 builds up

and R

across D

1

series resistance can be approximated using (see
figure 2):

Further information regarding the design of the mains
supply can be found in the data sheets in the appendix.
The reference voltage source on Pin 16 of typ. –8.9 V is
derived from the supply voltage and is used for
regulation.

Operation using an externally stabilised DC voltage is not
recommended.

If the supply cannot be taken directly from the mains
because the power dissipation in R
then the circuit shown in the following figure 3 should be
used.

and is smoothed by C1. The value of the

1

V

–V

M

2I

S

S

would be too large,

1

+

R

1

U211B2/ B3

When the potential on Pin 7 reaches the nominal value
predetermined at Pin 12, then a trigger pulse is generated
whose width t

and hence the pulse width can be evaluated by

of C

2

is determined by the value of C

p

assuming 8 ms/nF). At the same time, a latch is set, so that
as long as the automatic retriggering has not been
activated, then no more pulses can be generated in that
half cycle.

The current sensor on Pin 1 ensures that, for operations
with inductive loads, no pulse will be generated in a new
half-cycle as long as a current from the previous half
cycle is still flowing in the opposite direction to the
supply voltage at that instant. This makes sure that “gaps”
in the load current are prevented.

The control signal on Pin 12 can be in the range 0 V to
–7 V (reference point Pin 2).

= –7 V then the phase angle is at maximum =

If V

12

i.e., the current flow angle is a minimum. The phase angle

a

is minimum when V

min

= V2.

12

(the value

2

a

max

~

24 V~

123

C

R

1

Figure 3. Supply voltage for high current requirements

1

4

95 10362

5

Phase Control

There is a general explanation in the data sheet,
TEA1007, on the common phase control function. The
phase angle of the trigger pulse is derived by comparing
the ramp voltage (which is mains synchronized by the
voltage detector) with the set value on the control input
Pin 12. The slope of the ramp is determined by C
charging current. The charging current can be varied
using R
also be adjusted using R

on Pin 6. The maximum phase angle

2

.

2

2

a

max

and its

can

Voltage Monitoring

As the voltage is built up, uncontrolled output pulses are
avoided by internal voltage surveillance. At the same
time, all of the latches in the circuit (phase control, load
limit regulation, soft start) are reset and the soft-start
capacitor is short circuited. Used with a switching
hysteresis of 300 mV, this system guarantees defined
start-up behavior each time the supply voltage is switched
on or after short interruptions of the mains supply.

Soft-Start

As soon as the supply voltage builds up (t1), the integrated
soft-start is initiated. The figure below shows the
behaviour of the voltage across the soft-start capacitor
and is identical with the voltage on the phase control input
on Pin 12. This behaviour guarantees a gentle start-up for
the motor and automatically ensures the optimum run-up
time.

TELEFUNKEN Semiconductors

Rev . A1, 29-May-96

3 (20)

U211B2/ B3

V

C3

V

12

V

0

t

1

t

2

Figure 4. Soft-start

t

3

t

tot

95 10272

t

t1 = build-up of supply voltage

= charging of C3 to starting voltage

t

2

+ t2 = dead time

t

1

= run-up time

t

3

= total start-up time to required speed

t

tot

C

is first charged up to the starting voltage V

3

typical 45 mA current (t

). By then reducing the charging

2

0

with

current to approx. 4 mA, the slope of the charging function
is substantially reduced so that the rotational speed of the
motor only slowly increases. The charging current then
increases as the voltage across C

increases giving a

3

progressively rising charging function which accelerates
the motor more and more strongly with increasing
rotational speed. The charging function determines the
acceleration up to the set-point. The charging current can
have a maximum value of 55 mA.

Frequency to Voltage Converter

The internal frequency to voltage converter (f/V­converter) generates a DC signal on Pin 10 which is
proportional to the rotational speed using an AC signal
from a tacho-generator or a light beam whose frequency
is in turn dependent on the rotational speed. The high
impedance input Pin 8, compares the tacho-voltage to a
switch-on threshold of typ. –100 mV. The switch-off
threshold is given with –50 mV. The hysteresis
guarantees very reliable operation even when relatively
simple tacho-generators are used. The tacho-frequency is
given by:

n

f

+

60

where: n = revolutions per minute

p(Hz)

p = number of pulses per revolution

The converter is based on the charge pumping principle.
With each negative half wave of the input signal, a
quantity of charge determined by C
amplified and then integrated by C

is internally

5

at the converter

6

output on Pin 10. The conversion constant is determined

, its charge transfer voltage of Vch, R6 (Pin 10) and

by C

5

the internally adjusted charge transfer gain.

I

10

ƪ

ƫ

G

k = G

+

i

8.3

I

9

C5 R6 V

i

ch

The analog output voltage is given by

V

= k @ f

O

The values of C

and C

5

must be such that for the highest

6

possible input frequency, the maximum output voltage

does not exceed 6 V. While C5 is charging up, the R

V

O

on Pin 9 is .approx. 6.7 kW. To obtain good linearity of the
f/V converter the time constant resulting from R

and C

i

should be considerably less (1/5) than the time span of the
negative half-cycle for the highest possible input
frequency. The amount of remaining ripple on the output

, C

voltage on Pin 10 is dependent on C

and the internal

5

6

charge amplification.

Gi Vch C

=

∆V

O

The ripple ∆V

. However, the increasing speed will then also be

C

6

C

6

can be reduced by using larger values of

o

5

reduced.
The value of this capacitor should be chosen to fit the

particular control loop where it is going to be used.

Pulse Blocking

The output of pulses can be blocked using Pin 18 (standby
operation) and the system reset via the voltage monitor if

≥ –1.25 V. After cycling through the switching point

V

18

hysteresis, the output is released when V
followed by a soft-start such as that after turn on.

Monitoring of the rotation can be carried out by
connecting an RC network to Pin 18. In the event of a
short or open circuit, the triac triggering pulses are cut off
by the time delay which is determined by R and C. The
capacitor C is discharged via an internal resistance

= 2 kW with each charge transfer process of the f/V

R

i

converter. If there are no more charge transfer processes
C is charged up via R until the switch-off threshold is
exceeded and the triac triggering pulses are cut off. For
operation without trigger pulse blocking or monitoring of
the rotation, Pins 18 and 16 must be connected together.

≤ –1.5 V

18

i

5

4 (20)

TELEFUNKEN Semiconductors

Rev . A1, 29-May-96

C = 1 F

10 V

R = 1 M

18



123

Figure 5. Operation delay

17 16 15

4

95 10363

Control Amplifier (Figure 2)

The integrated control amplifier with differential input
compares the set value (Pin 11) with the instantaneous
value on Pin 10 and generates a regulating voltage on the
output Pin 12 (together with the external circuitry on
Pin 12) which always tries to hold the actual voltage at the
value of the set voltages. The amplifier has a
transmittance of typically 1000 A/V and a bipolar
current source output on Pin 12 which operates with
typically ±110 A. The amplification and frequency
response are determined by R
out). For open loop operation, C

can be omitted. Pin 10 should be connected with

R

11

, C7, C8 and R11 (can be left

7

, C5, R6, R7, C7, C8 and

4

Pin 12 and Pin 8 with Pin 2. The phase angle of the
triggering pulse can be adjusted using the voltage on
Pin 11. An internal limitation circuit prevents the voltage
on Pin 12 from becoming more negative than V

+ 1 V.

16

Load Limitation

The load limitation, with standard circuitry, provides
absolute protection against overloading of the motor. the
function of the load limiting takes account of the fact that
motors operating at higher speeds can safely withstand
large power dissipations than at lower speeds due to the
increased action of the cooling fan. Similary, consider­ations have been made for short term overloads for the
motor which are, in practice, often required. These
finctions are not damaging and can be tolerated.

In each positive half-cycle, the circuit measures via R
the load current on Pin 14 as a potential drop across R
and produces a current proportional to the voltage on
Pin 14. This current is available on Pin 15 and is
integrated by C
a large phase angle for current flow, the voltage on C
exceeds an internally set threshold of approx. 7.3 V

. If, following high current amplitudes or

9

U211B2/ B3

(reference voltage Pin 16) then a latch is set and the load
limiting is turned on. A current source (sink) controlled
by the control voltage on Pin 15 now draws current from
Pin 12 and lowers the control voltage on Pin 12 so that the
phase angle  is increased to

The simultaneous reduction of the phase angle during
which current flows causes firstly: a reduction of the
rotational speed of the motor which can even drop to zero
if the angular momentum of the motor is excessively
large, and secondly: a reduction of the potential on C
which in turn reduces the influence of the current sink on
Pin 12. The control voltage can then increase again and
bring down the phase angle. This cycle of action sets up
a “balanced condition” between the “current integral” on
Pin 15 and the control voltage on Pin 12.

Apart from the amplitude of the load current and the time
during which current flows, the potential on Pin 12 and
hence the rotational speed also affects the function of the
load limiting. A current proportional to the potential on
Pin 10 gives rise to a voltage drop across R
so that the current measured on Pin 14 is smaller than the
actual current through R

.

8

This means that higher rotational speeds and higher
current amplitudes lead to the same current integral.
Therefore, at higher speeds, the power dissipation must
be greater than that at lower speeds before the internal
threshold voltage on Pin 15 is exceeded. The effect of
speed on the maximum power is determined by the
resistor R

and can therefore be adjusted to suit each

10

individual application.
If, after the load limiting has been turned on, the

momentum of the load sinks below the “o-momentum”
set using R

, then V15 will be reduced. V12 can then in-

10

crease again so that the phase angle is reduced. A smaller
phase angel corresponds to a larger momentum of the mo­tor and hence the motor runs up - as long as this is allowed
by the load momentum. For an already rotating machine,
the effect of rotation on the measured “current integral”
ensures that the power dissipation is able to increase with
the rotational speed. the result is: a current controlled
accelleration run-up., which ends in a small peak of accel­leraton when the set point is reached. The latch of the load
limiting is simultaneously reset. The speed of the motor
is then again under control and it is capable of carrying its
full load. The above mentioned peak of accelleration

10

depends upon the ripple of actual speed voltage. A large

8

amount of ripple also leads to a large peak of
accelleration.

The measuring resistor R
ensures that the amplitude of the voltage across it does not

9

8

exceed 600 mV.

.



max

10

should have a value which

9

, via Pin 14,

TELEFUNKEN Semiconductors

Rev . A1, 29-May-96

5 (20)

U211B2/ B3

Design Hints

Practical trials are normally needed for the exact
determination of the values of the relevant components in
the load limiting. To make this evaluation easier, the

following table shows the effect of the circuitry on the
important parameters of the load limiting and summarises
the general tendencies.

Parameters

R

10

P

max

P

min

P

/

max

min

t

d

t

r

P

– maximum continuous power dissipation P1 = f

max

– power dissipation with no rotation P1 = f

P

min

– operation delay time

t

d

– recovery time

t

r

increases decreases n.e.
increases decreases n.e.
increases n.e. n.e.
n.e. decreases increases
n.e. increases increases

n.e – no effect

Pulse Output Stage

The pulse output stage is short circuit protected and can
typically deliver currents of 125 mA. For the design of
smaller triggering currents, the function I

= f(RGT) has

GT

been given in the data sheets in the appendix.

Automatic Retriggering

The variable automatic retriggering prevents half cycles
without current flow, even if the triac is turned off earlier
e.g. due to a collector which is not exactly centered (brush
lifter) or in the event of unsuccessful triggering. If it is
necessary, another triggering pulse is generated after a
time lapse which is determined by the repetition rate set
by resistance between Pin 5 and Pin 3 (R
maximum repetition rate (Pin 5 directly connected to
Pin 3), the next attempt to trigger comes after a pause of

and this is repeated until either the triac fires or the

4.5 t

p

half-cycle finishes. If Pin 5 is connected, then only one
trigger pulse per half-cycle is generated. Because the
value of R
repetition rate set using R

.

of C

2

determines the charging current of C2, any

5-3

is only valid for a fixed value

5-3

). With the

5-3

Component affected

R

9

n 0 0

(n)

n = 0

(n)

C

9

General Hints and Explanation of Terms

To ensure safe and trouble-free operation, the following
points should be taken into consideration when circuits
are being constructed or in the design of printed circuit
boards.

– The connecting lines from C

should be as short as possible: The connection to Pin 2
should not carry any additional high current such as
the load current. When selecting C
temperature coefficient is desirable.

– The common (earth) connections of the set-point

generator, the tacho-generator and the final
interference suppression capacitor C
converter should not carry load current.

– The tacho-generator should be mounted without

influence by strong stray fields from the motor.

– The connections from R

10

as possible.

To achieve a high noise immunity, a maximum ramp
voltage of 6 V should be used.

The typical resistance R

can be calculated from Iö as

ö

follows:

(kW)

R

ö

T(ms) 1.13(V) 10

+

CńnF) 6(V)

T = Period duration for mains frequency

(10 ms at 50 Hz)

C

= Ramp capacitor, max. ramp voltage 6 V

ö

and constant voltage drop at R

A 10% lower value of Rö (under worst case conditions)
is recommended.

to Pin 7 and Pin 2

2

and C

should be as short

5

, a low

2

of the f/V

4

3

= 1.13 V.

ö

6 (20)

TELEFUNKEN Semiconductors

Rev . A1, 29-May-96