VOICE CONTROL PROCESSOR LE79232 PRODUCT PREVIEW Features Separate test-in and test-out busses allow simultaneous test-in and test-out access. The voltage sense is connected before the test-out relay, such that the impedance generation is preserved during test-in access or during self-test performed with the loop disconnected The test-out relay can be used to disconnect the loop during test-in access, in-service calibration, self-test, or to measure sensing offsets The LCAS is inside the impedance feedback loop and doesn't degrade the longitudinal balance In-service calibration can be performed using a central circuit connected to the test-in bus Self-test is performed using the calibration circuit or using a single test load resistor located on the test-in bus Foreign Voltage Testing Voltage range at the tip and ring port is ±200 V with typical secondary protection The LCAS break switches are used such that the SLIC leakage doesn't affect the results Measurement offsets can be calibrated by using the testout relay to disconnect the loop, or by applying a low impedance to ground on the test-in bus Foreign Current Testing Voltage range at the tip and ring port is VBH to ground, minus the saturation voltage at peak common-mode current The current sensing offset can be calibrated out by operating the test-out relay 3-Element Resistance Testing Current range is ±60 mA total common-mode current and ±80 mA differential and common mode current per individual lead Voltage range at the tip and ring port is VBH to ground, minus the saturation voltage at peak common-mode current The fixed part of the current sensing offset is cancelled in the test procedure by the two point measurement The variable part of the current sensing offset can be calibrated out by operating the test-out relay Fuse Test The fuse test can be done by executing a 3-element capacitance test in high gain mode with and without the test-out relay activated Loop Resistance Test The voltage sensing offset and the feed current offset are cancelled out by doing a positive and negative polarity measurement at each current level Current range is ±60 mA total common-mode current and ±80 mA differential and common mode current per individual lead Le79232 SLIC and External Ringing with Le75282 LCAS, Test-In Bus and Test-Out Bus Test-In Bus Test-Out Bus SA Fuse EMR AD TIP CFG Le79232 SLIC Device Le75282 LCAS SLAC I/O Secondary Protection OFF VBH P1 P3 P2 P2 P3 P1 Fuse BD RD1 EMR RING Test-Out Bus SB Test-Out Relay Test-In Bus Ring Generator Information relating to products and services furnished herein by Zarlink Semiconductor Inc. or its subsidiaries is believed to be reliable. The products, their specifications, services and other information appearing in this publication are subject to change by Zarlink without notice. ZARLINK, ZL, and the Zarlink logo are trademarks of Zarlink Semiconductor Inc. © 2010, Zarlink Semiconductor Inc. All Rights Reserved. Publication Number 10ZS231 www.ZARLINK.com