U210B
| Model | U210B |
| Description | Phase Control Circuit - Load Current Feedback Applications |
| PDF file | Total 15 pages (File size: 379K) |
| Chip Manufacturer | TEMIC |
U 210 B / U 210 B–FP
Soft–start
TELEFUNKEN Semiconductors
As soon as the supply voltage builds up (t
1
), 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 9. This
behaviour allows a gentle start–up for the motor.
Figure 4 Soft–start
C
3
is first charged with typ. 30
mA.
The charging current then increases as the voltage across C
4
increases giving a
progressively rising charging function with more and more strongly accelerates the motor with increasing rotational
speed. The charging function determines the acceleration up to the set point. The charging current can have a maximum
value of 85
mA.
Control amplifier
The integrated control amplifier with differential input has a bipolar current output, with typically
±110
mA
at Pin 9 and
a transmittance of typ. 1000
mA/V.
The amplification and frequency response are determined by external circuit. For
operation as a power control, it should be connected with Pin 7. Phase angle of the firing pulse can be adjusted by using
the voltage at Pin 8. An internal limiting circuit prevents the voltage on Pin 9 becoming more negative than V
13
+ 1 V.
Load current detection, Figure 2
Voltage drop across R
8
, dependent of load current, generates an input–current at Pin 11 limited by R
5
. Proportional output
current of 0.44 x I
11
(CTR) is available at Pin 12. It is proportional with respect to phase and amplitude of load current.
Capacitor C
3
integrates the current whereas resistor R
7
evaluates it. The voltage obtained due to load current
proportionality, can be used according to the application i.e., load current compensation or load current regulation.
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
GT
= f (R
GT
) has been given in the data sheets in the appendix. In contrast to the U 111 B
and the TEA 1007, the pulse output stage of the U 210 B has no gate bypass resistor.
Automatic retriggering
The automatic retriggering prevents half cycles without current flow, even if the triac is turned off earlier e.g. due to not
exactly centred collector (brush lifter) or in the event of unsuccessful triggering. After a time lapse of t
pp
=4.5 t
p
is
generated another triggering pulse which is repeated until either the triac fires or the half cycle finishes.
4
Preliminary Information
