Cirrus Logic CS1616 - Manual (Page 3)

CS1615/16
DS961F1 3
2. PIN DESCRIPTION
Figure 2. CS1615/16 Pin Assignments
16-lead SOIC and TSSOP
16 Zero-current Detect FBAUX
15 No Connect NC
14 IC Supply Voltage VDD
13 GD Gate Drive
10 eOTP External Overtemperature Protection
11 FBSENSE Flyback Current Sense
12 GND Ground
9 LED Load Current CTRL2
No Connect NC 1
2 IAC Rectifier Voltage Sense
3 Voltage Clamp Current Source CLAMP
4 SGND Source Ground
5 Source Switch SOURCE
6 NC No Connect
7 No Connect NC
8 CTRL1 Dimmer Hold Current
Pin Name Pin # I/O Description
NC 1 IN No Connect — Leave pin unconnected.
IAC 2 IN
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.
CLAMP 3 OUT
Voltage Clamp Current Source — Connect to a voltage clamp circuit on the
source-switched dimmer-compatibility circuit.
SGND 4 PWR Source Ground — Common reference current return for the SOURCE pin.
SOURCE 5 IN
Source Switch — Connected to the source of the source-switched external high-volt-
age FET.
NC 6 IN No Connect — Connect this pin to VDD using a 47k  pull-up resistor.
NC 7 IN No Connect — Connect this pin to VDD using a 47k pull-up resistor.
CTRL1 8 IN
Dimmer Hold Current — Connect a resistor to this pin to set the minimum input cur-
rent being pulled by the flyback/buck-boost stage.
CTRL2 9 IN LED Load Current — Connect a resistor to this pin to set the LED current.
eOTP 10 IN
External Overtemperature Protection — Connect an external NTC thermistor to this
pin, allowing the internal A/D converter to sample the change to NTC resistance.
FBSENSE 11 IN
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.
GND 12 PWR
Ground — Common reference. Current return for both the input signal portion of the
IC and the gate driver.
GD 13 OUT Gate Drive — Gate drive for the power FET.
VDD 14 PWR
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.
NC 15 - No Connect — Leave pin unconnected.
FBAUX 16 IN
Zero-current Detect — Connect to the flyback/buck-boost inductor auxiliary winding
for demagnetization current zero-crossing detection.