UAA2016
CIRCUIT FUNCTIONAL DESCRIPTION
Power Supply (Pin 5 and Pin 7)
case the level is set at 5°C. This configuration can be useful
for low temperature inertia systems.
The application uses a current source supplied by a single
high voltage rectifier in series with a power dropping resistor.
Sawtooth Generator
An integrated shunt regulator delivers a V
voltage of
EE
In order to comply with European norms, the ON/OFF
period on the load must exceed 30 seconds. This is achieved
by an internal digital sawtooth which performs the
proportional regulation without any additional component.
The sawtooth signal is added to the reference applied to the
comparator negative input. Figure 2 shows the regulation
improvement using the proportional band action.
– 8.6 V with respect to Pin 7. The current used by the total
regulating system can be shared in four functional blocks: IC
supply, sensing bridge, triac gate firing pulses and zener
current. The integrated zener, as in any shunt regulator,
absorbs the excess supply current. The 50 Hz pulsed supply
current is smoothed by the large value capacitor connected
between Pins 5 and 7.
Noise Immunity
Temperature Sensing (Pin 3)
The noisy environment requires good immunity. Both the
voltage reference and the comparator hysteresis minimize
the noise effect on the comparator input. In addition the
effective triac triggering is enabled every 1/3 sec.
The actual temperature is sensed by a negative
temperature coefficient element connected in a resistor
divider fashion. This two element network is connected
between the ground terminal Pin 5 and the reference voltage
– 5.5 V available on Pin 1. The resulting voltage, a function of
the measured temperature, is applied to Pin 3 and internally
compared to a control voltage whose value depends on
several elements: Sawtooth, Temperature Reduction and
Hysteresis Adjust. (Refer to Application Information.)
Failsafe
Output pulses are inhibited by the “failsafe” circuit if the
comparator input voltage exceeds the specified threshold
voltage. This would occur if the temperature sensor circuit is
open.
Temperature Reduction
Sampling Full Wave Logic
For energy saving, a remotely programmable temperature
Two consecutive zero–crossing trigger pulses are
generated at every positive mains half–cycle. This ensures
that the number of delivered pulses is even in every case.
reduction is available on Pin 4. The choice of resistor R
1
connected between Pin 4 and V
reduction level.
sets the temperature
CC
The pulse length is selectable by R
connected on Pin 8.
sync
The pulse is centered on the zero–crossing mains waveform.
Comparator
When the positive input (Pin 3) receives a voltage greater
than the internal reference value, the comparator allows the
triggering logic to deliver pulses to the triac gate. To improve
the noise immunity, the comparator has an adjustable
Pulse Amplifier
The pulse amplifier circuit sinks current pulses from Pin 6
to V . The minimum amplitude is 70 mA. The triac is then
EE
triggered in quadrants II and III. The effective output current
hysteresis. The external resistor R connected to Pin 2 sets
3
amplitude is given by the external resistor R . Eventually,
an LED can be inserted in series with the Triac gate (see
Figure 1).
out
the hysteresis level. Setting Pin 2 open makes a 10 mV
hysteresis level, corresponding to 0.15°C. Maximum
hysteresis is obtained by connecting Pin 2 to V . In that
CC
Figure 5. Minimum Output Current
Figure 4. Output Resistor versus
versus Output Resistor
Triac Gate Current
200
100
180
160
140
80
60
40
T
= +10°C
A
120
100
80
T
= 0°C
A
T
= + 85°C
A
T
= – 20
°C
A
T
= – 20
140
°C
A
20
0
60
T
= –10°C
A
40
20
30
40
50
60
40
60
80
100
120
160
180
200
I
, TRIAC GATE CURRENT SPECIFIED AT 25°C (mA)
R
, OUTPUT RESISTOR (Ω)
GT
out
5
MOTOROLA ANALOG IC DEVICE DATA
5秒后页面跳转
PCF8574资料解读：主要参数分析、引脚说明
AD637数据手册解读：主要特性、引脚及其功能解读、电气参数
ADUM1201资料手册解读：参数分析、引脚说明、应用分析
一文带你了解压敏电阻器在直流电路中的过压保护作用
微信公众号
抖音公众号
浙公网安备 33010502006866号 浙ICP备10014259号-119
营业执照ICP证
数据手册
如果您发现信息不准确，
