Device

Operating

Temperature Range

Package

UAA2016

SEMICONDUCTOR

TECHNICAL DATA

ZERO VOLTAGE SWITCH

POWER CONTROLLER

ORDERING INFORMATION

UAA2016D

UAA2016P

TA = 20

to +85

SO8

Plastic DIP

Order this document by UAA2016/D

Vref 1

PIN CONNECTIONS

Hys. Adj.

Sensor

Temp. Reduc.

Sync

VCC

Output

VEE

(Top View)

P SUFFIX

PLASTIC PACKAGE

CASE 626

D SUFFIX

PLASTIC PACKAGE

CASE 751

(SO8)

MOTOROLA ANALOG IC DEVICE DATA

Product Preview

Zero Voltage Switch

Power Controller

The UAA2016 is designed to drive triacs with the Zero Voltage technique

which allows RFIfree power regulation of resistive loads. Operating directly
on the AC power line, its main application is the precision regulation of
electrical heating systems such as panel heaters or irons.

A builtin digital sawtooth waveform permits proportional temperature

regulation action over a

C band around the set point. For energy savings

there is a programmable temperature reduction function, and for security a
sensor failsafe inhibits output pulses when the sensor connection is broken.
Preset temperature (i.e. defrost) application is also possible. In applications
where high hysteresis is needed, its value can be adjusted up to 5

C around

the set point. All these features are implemented with a very low external
component count.

Zero Voltage Switch for Triacs, up to 2.0 kW (MAC212A8)

Direct AC Line Operation

Proportional Regulation of Temperature over a 1

C Band

Programmable Temperature Reduction

Preset Temperature (i.e. Defrost)

Sensor Failsafe

Adjustable Hysteresis

Low External Component Count

Representative Block Diagram

Sense Input

Sampling

Full Wave

Logic

1/2

Failsafe

Hysteresis

Adjust

4Bit DAC

Temperature

Reduction

Voltage

Reference

Internal

Reference

VEE

Pulse

Amplifier

Supply

Voltage

Output

11Bit Counter

+VCC

Sync

UAA2016

Synchronization

This document contains information on a product under development. Motorola reserves the
right to change or discontinue this product without notice.

Motorola, Inc. 1996

Issue 5

UAA2016

MOTOROLA ANALOG IC DEVICE DATA

MAXIMUM RATINGS

(Voltages referenced to Pin 7)

Rating

Symbol

Value

Unit

Supply Current (IPin 5)

ICC

NonRepetitive Supply Current

(Pulse Width = 1.0

ICCP

200

AC Synchronization Current

Isync

3.0

Pin Voltages

VPin 2
VPin 3
VPin 4
VPin 6

0; Vref
0; Vref
0; Vref

0; VEE

Vref Current Sink

IPin 1

1.0

Output Current (Pin 6)

(Pulse Width < 400

150

Power Dissipation

625

Thermal Resistance, JunctiontoAir

100

C/W

Operating Temperature Range

20 to + 85

ELECTRICAL CHARACTERISTICS

(TA = 25

C, VEE = 7.0 V, voltages referred to Pin 7, unless otherwise noted.)

Characteristic

Symbol

Min

Typ

Max

Unit

Supply Current (Pins 6, 8 not connected)

(TA = 20

to + 85

ICC

0.9

1.5

Stabilized Supply Voltage (Pin 5) (ICC = 2.0 mA)

VEE

9.0

8.0

Reference Voltage (Pin 1)

Vref

6.5

5.5

4.5

Output Pulse Current (TA = 20

to + 85

(Rout = 60 W, VEE = 8.0 V)

100

130

Output Leakage Current (Vout = 0 V)

IOL

Output Pulse Width (TA = 20

to + 85

C) (Note 1)

(Mains = 220 Vrms, Rsync = 220 k

)

100

Comparator Offset (Note 5)

Voff

+10

Sensor Input Bias Current

IIB

0.1

Sawtooth Period (Note 2)

40.96

sec

Sawtooth Amplitude (Note 6)

Temperature Reduction Voltage (Note 3)

(Pin 4 Connected to VCC)

VTR

280

350

420

Internal Hysteresis Voltage

(Pin 2 Not Connected)

VIH

Additional Hysteresis (Note 4)

(Pin 2 Connected to VCC)

280

350

420

Failsafe Threshold (TA = 20

to + 85

C) (Note 7)

VFSth

180

300

NOTES: 1. Output pulses are centered with respect to zero crossing point. Pulse width is adjusted by the value of Rsync. Refer to application curves.

2. The actual sawtooth period depends on the AC power line frequency. It is exactly 2048 times the corresponding period. For the 50 Hz case it is 40.96

sec. For the 60 Hz case it is 34.13 sec. This is to comply with the European standard, namely that 2.0 kW loads cannot be connected or removed
from the line more than once every 30 sec.

3. 350 mV corresponds to 5

C temperature reduction. This is tested at probe using internal test pad. Smaller temperature reduction can be obtained by

adding an external resistor between Pin 4 and VCC. Refer to application curves.

4. 350 mV corresponds to a hysteresis of 5

C. This is tested at probe using internal test pad. Smaller additional hysteresis can be obtained by adding

an external resistor between Pin 2 and VCC. Refer to application curves.

5. Parameter guaranteed but not tested. Worst case 10 mV corresponds to 0.15

C shift on set point.

6. Measured at probe by internal test pad. 70 mV corresponds to 1

C. Note that the proportional band is independent of the NTC value.

7. At very low temperature the NTC resistor increases quickly. This can cause the sensor input voltage to reach the failsafe threshold, thus inhibiting

output pulses; refer to application schematics. The corresponding temperature is the limit at which the circuit works in the typical application. By
setting this threshold at 0.05 Vref, the NTC value can increase up to 20 times its nominal value, thus the application works below 20

UAA2016

MOTOROLA ANALOG IC DEVICE DATA

Load

MAC212A8

Rout

Rsync

VEE

Vref

Temp. Red.

Rdef

HysAdj

Figure 1. Application Schematic

Synchronization

11Bit Counter

4Bit DAC

UAA2016

1/2

Failsafe

Pulse

Amplifier

Sampling

Full Wave

Logic

Internal

Reference

Supply

Voltage

+VCC

Output

Sync

Sense Input

NTC

220 V

a
c

APPLICATION INFORMATION

(For simplicity, the LED in series with Rout is omitted in the

following calculations.)

Triac Choice and Rout Determination

Depending on the power in the load, choose the triac that

has the lowest peak gate trigger current. This will limit the
output current of the UAA2016 and thus its power
consumption. Use Figure 4 to determine Rout according to
the triac maximum gate current (IGT) and the application low
temperature limit. For a 2.0 kW load at 220 Vrms, a good triac
choice is the Motorola MAC212A8. Its maximum peak gate
trigger current at 25

C is 50 mA.

For an application to work down to 20

C, Rout should be

. It is assumed that: IGT(T) = IGT(25

exp (T/125)

with T in

C, which applies to the MAC212A8.

Output Pulse Width, Rsync

The pulse with TP is determined by the triac's IHold, ILatch

together with the load value and working conditions
(frequency and voltage):

Given the RMS AC voltage and the load power, the load

value is:

RL = V2rms/POWER

The load current is then:

Load

(Vrms

sin(2

ft)V

) R

where VTM is the maximum on state voltage of the triac, f is
the line frequency.

Set ILoad = ILatch for t = TP/2 to calculate TP.

Figures 6 and 7 give the value of TP which corresponds to

the higher of the values of IHold and ILatch, assuming that
VTM = 1.6 V. Figure 8 gives the Rsync that produces the
corresponding TP.

RSupply and Filter Capacitor

With the output current and the pulse width determined as

above, use Figures 9 and 10 to determine RSupply, assuming
that the sinking current at Vref pin (including NTC bridge
current) is less than 0.5 mA. Then use Figure 11 and 12 to
determine the filter capacitor (CF) according to the ripple
desired on supply voltage. The maximum ripple allowed is
1.0 V.

Temperature Reduction Determined by R1

(Refer to Figures 13 and 14.)

UAA2016

MOTOROLA ANALOG IC DEVICE DATA

CIRCUIT FUNCTIONAL DESCRIPTION

Power Supply (Pin 5 and Pin 7)

The application uses a current source supplied by a single

high voltage rectifier in series with a power dropping resistor.
An integrated shunt regulator delivers a VEE voltage of
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.

Temperature Sensing (Pin 3)

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.)

Temperature Reduction

For energy saving, a remotely programmable temperature

reduction is available on Pin 4. The choice of resistor R1
connected between Pin 4 and VCC sets the temperature
reduction level.

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
hysteresis. The external resistor R3 connected to Pin 2 sets
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 VCC. In that

case the level is set at 5

C. This configuration can be useful

for low temperature inertia systems.

Sawtooth Generator

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.

Noise Immunity

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.

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.

Sampling Full Wave Logic

Two consecutive zerocrossing trigger pulses are

generated at every positive mains halfcycle. This ensures
that the number of delivered pulses is even in every case.
The pulse length is selectable by Rsync connected on Pin 8.
The pulse is centered on the zerocrossing mains waveform.

Pulse Amplifier

The pulse amplifier circuit sinks current pulses from Pin 6

to VEE. The minimum amplitude is 70 mA. The triac is then
triggered in quadrants II and III. The effective output current
amplitude is given by the external resistor Rout. Eventually,
an LED can be inserted in series with the Triac gate (see
Figure 1).

TA = 20

TA = 0

140

200

Figure 4. Output Resistor versus

Triac Gate Current

IGT, TRIAC GATE CURRENT SPECIFIED AT 25

C (mA)

160

180

120

100

R , OUTPUT

RESIST

OR ( )

out

Figure 5. Minimum Output Current

versus Output Resistor

TA = 20

TA = + 85

200

180

160

140

120

100

Rout, OUTPUT RESISTOR (

)

I , MINIMUM OUTPUT

CURRENT

(mA)

Out(min)

TA = +10

TA = 10

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