Features
•
•
•
•
•
•
•
•
•
•
Full-wave Current Sensing
Mains Supply Variation Compensated
Programmable Load-current Limitation with Over- and High-load Output
Variable Soft Start
Voltage and Current Synchronization
Automatic Retriggering Switchable
Triggering Pulse Typically 125 mA
Internal Supply-voltage Monitoring
Current Requirement
≤
3 mA
Temperature-compensated Reference Voltage
Applications
•
Advanced Motor Control
•
Grinder
•
Drilling Machine
Phase-control
IC with Current
Feedback and
Overload
Protection
U2010B
1. Description
The U2010B is designed as a phase-control circuit in bipolar technology for motor
control applications with load-current feedback and overload protection. It enables
load-current detection and has a soft-start function as well as reference voltage
output.
Figure 1-1.
Block Diagram
15
Limiting
detector
Voltage
detector
14
Overload
Mains voltage
compensation
High load
Supply
voltage
10
G
N
D
13
12
11
Automatic
retriggering
Phase
control unit
ϕ
= f (V
4
)
Output
-
1
2
+
100%
70%
A
α
max
Current
detector
16
Pulse
output
1
Load
current
detector
2
Full wave
rectifier
B
Programmable Auto-
start
overload
protection
C
I
max
9
Voltage
monitoring
Level
shift
3
4
5
6
Soft
start
7
U2010B
Reference
voltage
8
Rev. 4766B–INDCO–10/05
Figure 1-2.
2
18 kΩ/2 W
R
1
R
2
330 kΩ
α
max
V
S
13
12
Supply
voltage
GND
10
11
Overload
Limiting
detector
High load
Voltage
detector
Mains voltage
compensation
C
1
22 µF
Load
15
14
R
8
470 kΩ
LED
D
1
D
3
Automatic
retriggering
100%
70%
Output
Current
detector
1
2
Full wave
rectifier
R
3
16
Voltage
monitoring
1
Level
shift
Load
current
detector
180
Ω
A
α
max
9
U2010B
Block Diagram with External Circuit
Mode
230 V ~
-
+
Phase
control unit
ϕ
= f(V
4
)
Programmable
overload
protection
B
Auto-
start
C
I
max
A
B
C
S
1
U2010B
R
4
3.3 kΩ
2
3
4
5
C
5
0.1 µF
C
3
10 nF
3.3 kΩ
P
1
R
10
50 kΩ
100 kΩ
Load current
compensation
0.15 µF
C
4
Soft
start
6
7
Reference
voltage
8
R
6
R
5
^
V
(R6)
= ±250 mV
R
11
1 MΩ
C
2
4.7 µF
Overload
threshold
R
14
Set point
C
7
1 µF
R
7
4766B–INDCO–10/05
U2010B
2. Pin Configuration
Figure 2-1.
Pinning DIP16/SO16
ISENSE 1
ISENSE 2
Cϕ
3
16 OUTPUT
15 VSYNC
14
13
12
11
10
9
VRϕ
CONTROL 4
U2010B
COMP
ILOAD
CSOFT
VREF
5
6
7
8
OVERLOAD
HIGH LOAD
VS
GND
MODE
Table 2-1.
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Pin Description
Symbol
ISENSE
ISENSE
Cϕ
CONTROL
COMP
ILOAD
CSOFT
VREF
MODE
GND
VS
HIGH LOAD
OVERLOAD
VRϕ
VSYNC
OUTPUT
Function
Load current sensing
Load current sensing
Ramp voltage
Control input
Compensation output
Load current limitation
Soft start
Reference voltage
Mode selection
Ground
Supply voltage
High load indication
Overload indication
Ramp current adjust
Voltage synchronization
Trigger output
3
4766B–INDCO–10/05
3. General Description
3.1
Mains Supply
The U2010B contains voltage limiting and can be connected with the mains supply via D
1
and
R
1
. Supply voltage – between pin 10 and pin 11 – is smoothed by C
1
.
In the case of V
6
≤
70% of the overload threshold voltage, pins 11 and 12 are connected inter-
nally whereby V
sat
≤
1.2 V. When
⏐
V
6
⏐ ≥ ⏐
V
T70
⏐
, the supply current flows across D
3
.
The series resistance R
1
can be calculated as follows:
V
mains
–
V
Smax
R
1max
= --------------------------------------
2
×
I
tot
where:
V
mains
V
Smax
I
tot
I
Smax
I
x
= Mains supply voltage
= Maximum supply voltage
= Total current consumption = I
Smax
+ I
x
= Maximum current consumption of the IC
= Current consumption of the external components
3.2
Voltage Monitoring
When the voltage is built up, uncontrolled output pulses are avoided by internal voltage monitor-
ing. Apart from that, all latches in the circuit (phase control, load limit regulation) are reset and
the soft-start capacitor is short-circuited. This guarantees a specified start-up behavior each time
the supply voltage is switched on or after short interruptions of the mains supply. Soft start is ini-
tiated after the supply voltage has been built up. This behavior guarantees a gentle start-up for
the motor and automatically ensures the optimum run-up time.
3.3
Phase Control
The function of the phase control is mainly identical to the well-known IC U211B. The phase
angle of the trigger pulse is derived by comparing the ramp voltage V
3
, which is mains-synchro-
nized by the voltage detector, with the set value on the control input, pin 4. The slope of the
ramp is determined by Cϕ and its charging current Iϕ. The charging current can be varied using
Rϕ at pin 14. The maximum phase angle,
α
max
, can also be adjusted by using Rϕ (minimum cur-
rent flow angle
ϕmin),
see
Figure 7-1 on page 10.
When the potential on pin 3 reaches the set point level of pin 4, a trigger pulse width, t
p
, is deter-
mined from the value of Cϕ (t
p
= 9 µs/nF). At the same time, a latch is set with the output pulse
as long as the automatic retriggering has not been activated. When this happens, no more
pulses can be generated in that half cycle. The control input at pin 4 (with respect to pin 10) has
an active range from V
8
to -1 V. When V
4
= V
8
, then the phase angle is at its maximum,
α
max
, i.e.,
the current flow angle is minimum. The minimum phase angle,
α
min
, is set with V
4
≥
-1 V.
4
U2010B
4766B–INDCO–10/05
U2010B
3.4
Automatic Retriggering
The current-detector circuit monitors the state of the triac after triggering by measuring the volt-
age drop at the triac gate. A current flow through the triac is recognized when the voltage drop
exceeds a threshold level of typically 40 mV.
If the triac is quenched within the relevant half-wave after triggering (for example owing to low
load currents before or after the zero crossing of the current wave, or for commutator motors,
owing to brush lifters), the automatic retriggering circuit ensures immediate retriggering, if nec-
essary with a high repetition rate, t
pp
/t
p
, until the triac remains reliably triggered.
3.5
Current Synchronization
Current synchronization fulfils two functions:
– Monitoring the current flow after triggering.
In case the triac extinguishes again or does not switch on, automatic triggering is
activated until the triggering is successful.
– Avoiding triggering due to an inductive load.
In the case of inductive load operation, the current synchronization ensures that in
the new half wave, no pulse will be enabled as long as there is a current available
from the previous half wave, which flows from the opposite polarity to the actual
supply voltage.
The current synchronization as described above is a special feature of the U2010B. The device
evaluates the voltage at the pulse output between gate and reference electrode of the triac. As a
result, no separate current synchronization input with specified series resistance is necessary.
3.6
Voltage Synchronization with Mains Voltage Compensation
The voltage detector synchronizes the reference ramp with the mains supply voltage. At the
same time, the mains-dependent input current at pin 15 is shaped and rectified internally. This
current activates the automatic retriggering and at the same time is available at pin 5. By suit-
able dimensioning, it is possible to obtain the specified compensation effect. Automatic
retriggering and mains voltage compensation are not activated until
⏐
V
15 - 10
⏐
increases to 8 V.
The resistance R
sync.
defines the width of the zero voltage cross over pulse, synchronization cur-
rent, and hence the mains supply voltage compensation current.
Figure 3-1.
Suppression of Mains Voltage Compensation and Automatic Retrigger
Mains
R
2
15
2x
C6V2
10
U2010B
If the mains voltage compensation and the automatic retriggering are not required, both func-
tions can be suppressed by limiting
⏐
V
15 - 10
⏐ ≤
7 V, see
Figure 3-1.
5
4766B–INDCO–10/05
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