CS1615/16
2. PIN DESCRIPTION
No Connect
Rectifier Voltage Sense
Voltage Clamp Current Source
Source Ground
Source Switch
No Connect
No Connect
Dimmer Hold Current
NC
IAC
CLAMP
SGND
SOURCE
NC
NC
CTRL1
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
FBAUX
NC
VDD
GD
GND
FBSENSE
eOTP
CTRL2
Zero-current Detect
No Connect
IC Supply Voltage
Gate Drive
Ground
Flyback Current Sense
External Overtemperature Protection
LED Load Current
16-lead SOIC and TSSOP
Figure 2. CS1615/16 Pin Assignments
Pin Name
NC
IAC
CLAMP
SGND
SOURCE
NC
NC
CTRL1
CTRL2
eOTP
FBSENSE
GND
GD
VDD
NC
FBAUX
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
I/O
IN
IN
OUT
PWR
IN
IN
IN
IN
IN
IN
IN
PWR
OUT
PWR
-
IN
Description
No Connect
— Leave pin unconnected.
Rectifier Voltage Sense
— A current proportional to the rectified line voltage is fed
into this pin. The current is measured with an A/D converter.
Voltage Clamp Current Source
— Connect to a voltage clamp circuit on the
source-switched dimmer-compatibility circuit.
Source Ground
— Common reference current return for the SOURCE pin.
Source Switch
— Connected to the source of the source-switched external high-volt-
age FET.
No Connect
— Connect this pin to VDD using a 47k pull-up resistor.
No Connect
— Connect this pin to VDD using a 47kpull-up resistor.
Dimmer Hold Current
— Connect a resistor to this pin to set the minimum input cur-
rent being pulled by the flyback/buck-boost stage.
LED Load Current
— Connect a resistor to this pin to set the LED current.
External Overtemperature Protection
— Connect an external NTC thermistor to this
pin, allowing the internal A/D converter to sample the change to NTC resistance.
Feedback Current Sense
— The current flowing in the power FET is sensed across a
resistor. The resulting voltage is applied to this pin and digitized for use by the compu-
tational logic to determine the FET's duty cycle.
Ground
— Common reference. Current return for both the input signal portion of the
IC and the gate driver.
Gate Drive
— Gate drive for the power FET.
IC Supply Voltage
— Connect a storage capacitor to this pin to serve as a reservoir
for operating current for the device, including the gate drive current to the power tran-
sistor.
No Connect
— Leave pin unconnected.
Zero-current Detect
— Connect to the flyback/buck-boost inductor auxiliary winding
for demagnetization current zero-crossing detection.
DS961F1
3
APEX [ CIRRUS LOGIC ]
