UAA2016AD View Datasheet(PDF) - ON Semiconductor
Part Name
Description
View to exact match
UAA2016AD Datasheet PDF : 12 Pages
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S2 S1
RS
UAA2016
Rdef
R2
R1
R3
3
Sense Input
4
Temp. Red.
Failsafe
+
−
Sampling
Full Wave
Logic
UAA2016
Pulse
Amplifier
++
1/2
+
Internal
Reference
2
HysAdj
1
Vref
4−Bit DAC
11−Bit Counter
Synchronization
Sync 8
Rsync
Supply
Voltage
VEE 5
RS
6
Rout
Output
7
+VCC
MAC212A8
CF
Load
Figure 1. Application Schematic
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 ON Semiconductor 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
60 W. It is assumed that: IGT(T) = IGT(25°C) 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:
ILoad + (Vrms Ǹ2
sin(2pft)–VTM)ńRL
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.)
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