LE57D121
Dual Channel SLIC (Subscriber Line Interface Circuit)
Overview
We are transitioning to Microchip; this page will be directed to Le57D121 product page at www.microchip.com.
The innovative Le57D121 dual-channel SLIC device is designed for high-density POTS applications requiring a small-footprint, low-power SLIC device. By combining a fully featured line interface of two channels into one SLIC device, the Le57D121 device enables the design of a low-cost, high performance, and fully programmable line interface for multiple country applications worldwide, including Ground Start and metering capability. The on-chip Thermal Management (TMG) feature allows for significantly reduced power dissipation on the device. Optional dual battery operation to reduce total power consumption is also available. The device is offered in a thermally efficient, space-saving 44-pin eTQFP package. The 12 x 12 mm footprint allows designers to make a dramatic increase in the density of lines on a board. The Le57D121 device is also designed to significantly reduce the number of external components required for line card design. Microsemi offers a range of compatible SLAC devices that perform the codec function in a line card. In particular, the Quad and Octal SLAC devices combined with the Le57D121 device provides a programmable line circuit that can be configured for varying requirements. |
Detailed Block Diagram

Features & Benefits
- Dual-Channel SLIC device with small footprint
- Loop start and Ground start support
- +5 V and battery supply required
- Optional dual battery operation
- -39 V to -60 V battery operation
- Supplies more than 20 mA into 2000 Ω from -48 V
- Programmable current limit
- On-chip Thermal Management (TMG) feature in all Active states
- Low standby power (24 mW per channel)
- Supports 2.0 Vrms metering applications
- Control states: Active and Active Metering (Normal and Reverse Polarity), Standby, Tip Open and Disconnect
- 3.3 V compatible to logic control inputs
- Power up in Disconnect state
- On-hook transmission in Active states
- Per-channel fault detection and indication
- Per-channel thermal shutdown
- Programmable Off Hook and Ground Start thresholds.
- Programmable ring-trip detect threshold
- Footprint compatible with Microsemi's Le57D111 Dual SLIC