CY8CLEDAC02 Cypress Semiconductor Corp, CY8CLEDAC02 Datasheet - Page 7

• Manufacturer Part Number: CY8CLEDAC02
• Description: IC CTLR AC-DC DIMMABLE LED 8SOIC
• Manufacturer: Cypress Semiconductor Corp
• Type: High Power, AC Input, Dimmabler

Specifications of CY8CLEDAC02

• Package / Case: 8-SOIC (3.9mm Width)
• Voltage - Supply: 8 V ~ 16 V
• Frequency: 200kHz
• Operating Temperature: -40°C ~ 85°C
• Number Of Outputs: 1
• Internal Switch(s): No
• Efficiency: 85%
• Topology: AC DC Offline Switcher
• Operating Supply Voltage: - 0.3 V to 18 V
• Maximum Supply Current: 20 mA
• Maximum Power Dissipation: 526 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Pin Count: 8
• Mounting: Surface Mount
• Operating Supply Voltage (max): 18V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Current - Output / Channel: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Dimmer Tracking and Phase Measurement
Dimmer detection and tracking algorithms depend on accurate
measurement of the V
the second cycle of the dimmer discovery process and is then
latched for use. Using the measured V
calculations rather than a constant value enables automatic 50
or 60 Hz operation.
The phase measurement algorithm uses an internal counter that
starts counting when the rising threshold on V
counts input voltage samples until the voltage is above the
threshold. The counter is synchronized with the measured V
period and is restarted on every rising threshold (as shown in
Figure
The dimmer phase is calculated as:
Equation 1
The calculated D
When D
Document Number: 001-54879 Rev. *C
D
PHASE
6).
PHASE
BOOST
V
LED_EN
V
V
CROSS
IN
LED
is less than 0.2, D
PHASE

ZCD Threshold
t
t
IN
PERIOD
CROSS
is then used to generate a signal D
period. The period is measured during
V
V
ZCD Threshold
CROSS
INA
t
RATIO
CROSS
t0
Figure 6. Dimmer Tracking and Phase Measurement
t
PERIOD
IN
is set to 0.02 and when
period in subsequent
IN
is exceeded and
Figure 5. Dimmer Detection
RATIO
t
CROSS
IN
.
D
cases D
Equation 2
where K1 and K2 are constants with values 1.63 and 0.3 respec-
tively.
The output power to the LED load is modulated by D
D
when D
load.
The voltage at the I
output LED current can be set at a nominal value and modulated
using the following equation:
Equation 3
This equation provides a mapping from the measured dimmer
phase to actual light output.
t
PERIOD
PHASE
RATIO
V
D
ISENSE
RATIO
is 1, 100 percent power is provided to the LED load, and
RATIO
RATIO
is greater than 0.8, D
of 0.1, 10 percent power is provided to the LED
is set using the following equation:


V
D
I
SENSE
PHASE
SENSE
pin V
(

NOM
RATIO
K
ISENSE
)
1
is set to 1.0. For all other
CY8CLEDAC02


, which modulates the
D
K
RATIO
2
Page 7 of 20
RATIO
. When
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