4

10

6

F0

Mode control input.

11

7

E0

Detector Output Selection Input. This TTL input controls the multiplexing of the SHD (E0 = 1) and GKD (E0 = 0)

comparator outputs to the DET output based upon the state at the F2-F0 pins (see the Device Operating Modes table

shown on page 2).

12

9

DET

Detector Output - This TTL output provides on-hook/off-hook status of the loop based upon the selected operating

mode. The detected output will either be switch hook, ground key or ring trip (see the Device Operating Modes table

shown on page 2). DET will be latched low following a ring trip. Unlatching the DET pin is accomplished by changing

logic state.

13

10

ALM

Thermal Shutdown Alarm. This pin signals the internal die temperature has exceeded safe operating temperature

(approximately 175°C) and the device has been powered down automatically.

14

11

AGND

Analog ground reference. This pin should be externally connected to BGND.

15

12

BSEL

Selects between high and low battery, with a logic “1” selecting the high battery and logic “0” the low battery.

16

13

TL

Programming pin for the transient current limit feature, set by an external resistor to ground.

17

14

POL

External capacitor on this pin sets the polarity reversal time.

18

15

VRS

Ringing Signal Input - Analog input for driving 2-wire interface while in Ring Mode.

19

17

AUX

Auxiliary input - Float if not used.

20

18

VTX

Transmit Output Voltage - Output of impedance matching amplifier, AC couples through a resistor to CODEC.

21

19

VFB

Feedback voltage for impedance matching. This voltage is scaled to accomplish impedance matching. The CFB

capacitor connects between this pin and the -IN pin. The CFB cap needs to be non-polarized for proper device

operation in the Reverse Active mode. Ceramic surface mount capacitors (1206 body style) are available from

Panasonic with a 6.3V voltage rating. These can be used for CFB since it is internally limited to approximately ±3V.

22

20

-IN

23

21

VCC

Positive voltage power supply,+3.3V

24

22

CDC

polarized with a 6.3V voltage rating.

25

23

RT

Ring trip filter network.

26

24

ILIM

Loop Current Limit programming resistor.

27

25

SH

Switch hook detection threshold programming resistor.

---

26

SCC

Substrate Common Connection - Connect this pin to VBH Supply. This pin is used to connect the substrate of the die

and the thermal heatsink plane of the QFN package.

28

27

RING

RING power amplifier output.

PLCC

QFN

SYMBOL

DESCRIPTION

ISL5585