T7502 | DigiCamel IC Datasheet

Online Datasheet

Read T7502 online.

T7502 AGERE | Alldatasheet

Document overview

Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
PDF pages: 16

Technical content

Features

n +5 V only n Automatic powerdown mode n Low-power, latch-up-free CMOS technology n On-chip sample and hold, autozero, and precision voltage reference n Differential architecture for high noise immunity and power supply rejection n Automatic master clock frequency selection n 2.048 MHz or 4.096 MHz ﬁxed data rate n Frame sync controlled channel swapping n Differential analog I/O n 300 W output drivers n Operating temperature range: –40 C to +85 C n A-law companding

Applications

n Speakerphone n Telephone answering device (TAD) n POTS for ISDN

Description

The T7502 device is a single-chip, two-channel A-law PCM codec with ﬁlters. This integrated circuit provides analog-to-digital and digital-to-analog conversion. It provides the transmit and receive ﬁltering necessary to interface a voice telephone circuit to a time-division multiplexed (TDM) system. The device features a differential transmit ampliﬁer, and the power receive ampliﬁer is capable of driving 600 W differentially. PCM timing is deﬁned by a single frame sync pulse. This device operates in a delayed timing mode (digital data is valid one clock cycle after frame sync goes high). The T7502 is packaged in a 20-pin SOJ. Figure 1. Block Diagram

indicates a pull-down device is included on this lead. Table 1. Pin Descriptions Voice Frequency Transmitter Negative Input. uncommitted operational amplifier at the transmit filter input. Voice Frequency Transmitter Positive Input. uncommitted operational amplifier at the transmit filter input. er. The pin is the input to the transmit differential filters. Voice Frequency Receiver Positive Output. Voice Frequency Receiver Negative Output. and digital internal circuits. serves both analog and digital internal circuits. 8 bits for channel 1) are entered after the FS pulse has been detected. is shifted out on the rising edge of MCLK. . Ground connection for the digital circuitry.

4 Lucent Technologies Inc. Data Sheet February 1998T7502 Dual PCM Codec with Filters Absolute Maximum Ratings Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are absolute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess of those given in the operational sections of this data sheet. Exposure to absolute maximum ratings for extended periods can adversely affect device reliability. Handling Precautions Although protection circuitry has been designed into this device, proper precautions should be taken to avoid exposure to electrostatic discharge (ESD) during handling and mounting. Lucent Technologies Microelectronics Group employs a human-body model (HBM) and a charged-device model (CDM) for ESD-susceptibility testing and protection design evaluation. ESD voltage thresholds are dependent on the circuit parameters used to deﬁne the model. No industry-wide standard has been adopted for CDM. However, a standard HBM (resistance = 1500 W capacitance = 100 pF) is widely used and therefore can be used for comparison purposes. The HBM ESD threshold presented here was obtained by using these circuit parameters:

Electrical Characteristics

Speciﬁcations apply for T A = –40 C to +85 C, V DD = 5 V 5%, MCLK = either 2.048 MHz or 4.096 MHz, and GND = 0 V, unless otherwise noted. dc Characteristics Table 2. Digital Interface

Table 3. Power Dissipation Power measurements are made at MCLK = 4.096 MHz, outputs unloaded. Table 4. Analog Interface

Unless otherwise noted, the analog input is a 0 dBm0, 1020 Hz sine wave; the input ampliﬁer is set for unity gain. an ideal encoder. The output level is sin(x)/x-corrected. Table 5. Absolute Gain Table 6. Gain Tracking Table 7. Distortion

0.775 Vrms A-law,

Table 9. Noise Table 10. Receive Gain Relative to Gain at 1.02 kHz Table 11. Transmit Gain Relative to Gain at 1.02 kHz Power Supply Rejection ReceivePSR X PCM code is positive one LSB.

4600 Hz—7600 Hz

7600 Hz—8400 Hz

8400 Hz—50 kHz

as possible (while maintaining the load on GSX above 10 kW per Table 4) to minimize crosstalk. as possible (while maintaining the load on GSX above 10 kW per Table 4) to minimize crosstalk. Table 12. Interchannel Crosstalk (Between Channels) RF = £400 kW * Table 13. Intrachannel Crosstalk (Within Channels) RF = £400 kW *

Table 14. Clock Section (See Figures 5 and 6.)

Timing parameter tMCHDZ is referenced to a high-impedance state.

Table 16. Receive Section (See Figures 5 and 6.) Table 15. Transmit Section (See Figures 5 and 6.)

Figure 5. Short FS Transmit and Receive Timing (Channel 0 First) Figure 6. Long FS Transmit and Receive Timing (Channel 1 First)

4 BIT5

12 Lucent Technologies Inc. Data Sheet February 1998T7502 Dual PCM Codec with Filters Figure 7 shows one possible analog connection. Fully differential structures used for the inputs minimize the noise gain from the internal 2.4 V bias voltage to the output of the single-ended transmitter op amp. The forward path gain is G, and by using resistors on the positive side that are a factor of 1/(2G + 1) of those on the negative side, the microphone and transformer feeds are kept well balanced. Using this ratio, G can be as low as unity (0 dB) without exceeding the common-mode limit of the op amp. Users have wide latitude when selecting between a balanced ampliﬁer conﬁguration or a single-ended conﬁguration. Single-ended conﬁgurations usually need fewer external components (e.g., R IP = ¥ and RFP = 0 in Figure 2) but have two disadvantages: one, dc blocking from the source is typically required; two, internally generated noise at the common-mode pin VCM0 or VCM1 is ampliﬁed by G. For G > 10 (20 dB), this noise gain can become the factor that could limit performance. Single-ended conﬁgurations can be used even with microphones and transformers (R IP = 0 in these cases), but parasitic issues become somewhat more complex; so single-ended conﬁgurations are only suggested for gains of four (12 dB) or less. 5-3789.c Figure 7. Typical T7502 Application

2.4 VT7502 CENTRAL

Lucent Technologies Inc. 13 Data Sheet February 1998 T7502 Dual PCM Codec with Filters Outline Diagram 20-Pin SOJ Controlling dimensions are in inches. 5-4413r4 Package (N) Maximum Length (L) Maximum Width Without Leads (B) Maximum Width Including Leads (W) Maximum Height Above Board (H) SOJ (Small Outline, J-Lead) 20 12.95 7.62 8.81 3.18 N B PIN #1 IDENTIFIER ZONE L

0.51 MAX

H

0.79 MAX

0.10 SEATING PLANE

1.27 TYP

W

14 Lucent Technologies Inc. Data Sheet February 1998T7502 Dual PCM Codec with Filters

Ordering Information

Device Code Package Temperature Comcode T - 7502 - - - EL 20-Pin SOJ –40 °C to +85 °C 107622888

Lucent Technologies Inc. 15 Data Sheet February 1998 T7502 Dual PCM Codec with Filters Notes

February 1998T7502 Dual PCM Codec with Filters For additional information, contact your Microelectronics Group Account Manager or the following: INTERNE T: http://www .lucent.com/micro E-MAIL: docmaster@mic ro.lucent.com U.S.A.: Microelectronics Group, Lucent Technologies Inc., 555 Union Boulevard, Room 30L-15P-BA, Allentown, PA 18103 1-800-372-2447, FAX 610-712-4106 (In CANADA: 1-800-553-2448, FAX 610-712-4106) ASIA PACIFIC: Microelectronics Group, Lucent Technologies Singapore Pte. Ltd., 77 Science Park Drive, #03-18 Cintech III, Singapore 118256 Tel. (65) 778 8833, FAX (65) 777 7495 JAPAN: Microelectronics Group, Lucent Technologies Japan Ltd., 7-18, Higashi-Gotanda 2-chome, Shinagaw a-ku, Tokyo 141, Japan Tel. (81) 3 5421 1600, FAX (81) 3 5421 1700 EU R OPE: Data Requests: MICR OELECT R ONICS G R OUP DATALINE: Tel. (44) 1189 324 299, FAX (44) 1189 328 148 Technical Inquiries:GERMAN Y: (49) 89 95086 0 (Munich), UNITED KINGDOM: (44) 1344 865 900 (Bracknell), FRANCE : (33) 1 41 45 77 00 (Paris), SWEDEN: (46) 8 600 7070 (Stockholm), FINLAND: (358) 9 4354 2800 (Helsinki), ITALY: (39) 2 6601 1800 (Milan), SPAIN: (34) 1 807 1441 (Madrid) Lucent Technologies Inc. reserves the right to make changes to the product(s) or information contained herein without notice. No liability is assumed as a result of their use or application. No rights under any patent accompany the sale of any such product(s) or information. Co pyright © 1998 Lucent Technologies Inc. All Rights Reserved February 1998 DS98-096ALC (Replaces DS96-372ALC) Printed On Recycled Paper

Product Information

T7502 specifications and overview.

Summary

T7502 Dual PCM Codec with Filters February 1998

Description

The T7502 device is a single-chip, two-channel A-law PCM codec with filters. This integrated circuit provides analog-to-digital and digital-to-analog conversion. It provides the transmit and receive filtering necessary to interface a voice telephone circuit to a time-division multiplexed (TDM) system. The device features a differential transmit amplifier, and the power receive amplifier is capable of driving 600 Ω differentially. PCM timing is defined by a single frame sync pulse. This device operates in a delayed timing mode (digital data is valid one clock cycle after frame sync goes high). The T7502 is packaged in a 20-pin SOJ.

Source title T7502 Datasheet(PDF) - Agere Systems

Related Parts

More parts from the same family.

Browse manufacturer