My Inquiry
My Account
Analog Devices Inc./Maxim Integrated DS21Q44T
- Part No.:
- DS21Q44T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Telecom
- Package:
- 128-LQFP
- Datasheet:
-
DS21Q44T.pdf
- Description:
- IC TELECOM INTERFACE 128LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,917
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
DS21Q44T from Maxim Integrated is an enhanced quad E1 framer IC designed for CEPT/PCM-30 and ISDN-PRI telecommunication line interface systems. It integrates four fully independent E1 framers, each supporting FAS/CAS/CCS/CRC4 framing, dual two-frame elastic stores (up to 8.192 MHz), and a programmable 8-bit parallel control port compatible with Intel/Motorola buses. Used in carrier-grade access multiplexers and TDM switching gateways requiring precise E1 signal conditioning and CAS signaling extraction/insertion.
For engineers reviewing the DS21Q44T datasheet, DS21Q44T pinout, DS21Q44T application, or DS21Q44T equivalent, key selection considerations include per-framer elastic store independence, IEEE 1149.1 JTAG support, 3.3V supply with 5V-tolerant I/O, 128-pin TQFP package compatibility, and full compliance with ITU-T G.704/G.706/G.962/I.431 and ETSI 300 011/300 233 standards.
Technical Context
The DS21Q44T implements four completely autonomous E1 framers-no shared framing synchronizer-each with dedicated receive framer, receive elastic store, transmit formatter, and transmit elastic store. Each framer supports independent configuration of frame alignment (FAS), CRC4, CAS, and CCS modes, plus programmable output clocks for Fractional E1, H0, and H12 applications.
Its dual two-frame elastic store architecture enables asynchronous backplane interfacing up to 8.192 MHz, while the integrated HDLC controller (64-byte TX/RX buffers) supports Sa-bit or DS0-level access. Alarm detection includes AIS, remote alarm, remote multiframe alarm, RCL, RLOS, RRA, and RUA1-all generating state-change interrupts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| E1 Channels | 4 independent E1 framers, each handling full 2.048 Mbps PCM-30/CEPT or ISDN-PRI traffic |
| Framing Standards | Fully compliant with ITU-T G.704, G.706, G.962, I.431 and ETSI 300 011/300 233 |
| Elastic Store Clock | Dual two-frame elastic stores per framer, operable up to 8.192 MHz for asynchronous backplane sync |
| Control Interface | 8-bit parallel port, multiplexed/nonmultiplexed, Intel/Motorola bus compatible, with framer-select addressing |
| Supply & I/O | 3.3V core supply with 5V-tolerant I/O pins; supports industrial temperature range (0°C to +70°C) |
| JTAG Support | IEEE 1149.1 boundary-scan architecture with dedicated JTMS/JTCK/JTDI/JTDO/JTRST pins |
| HDLC Engine | Integrated HDLC controller with 64-byte TX/RX buffers, configurable for Sa-bit or DS0 channel access |
Pinout & Package
DS21Q44T is housed in a 128-pin Thin Quad Flat Package (TQFP), RoHS-compliant, with exposed thermal pad. Pin functions are organized per framer (0–3), supporting independent transmit/receive paths, elastic store clocks (RSYSCLK/TSYSCLK), signaling I/O (RSIG/TSIG), and system-level control (INT*, CS*, RD*, WR*, FS0/FS1).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| RCLK0–RCLK3 | Receive Clock Input | 2.048 MHz reference clock input per framer; drives internal receive framer logic and timing |
| TCLK0–TCLK3 | Transmit Clock Input | 2.048 MHz primary transmit clock per framer; controls transmit formatter data rate and timing |
| RSIG0–RSIG3 | Receive Signaling Output | Extracted CAS signaling bits per framer; available as parallel 8-bit stream synchronized to RCHCLK |
| TSIG0–TSIG3 | Transmit Signaling Input | Accepts external CAS signaling data for insertion into outgoing E1 frames; sampled on TCLK/TSYSCLK edge |
| INT* | Alarm Interrupt Output | Active-low open-drain interrupt aggregating RLOS, AIS, RRA, RUA1, and code violation alarms across all four framers |
| FS0/FS1 | Framer Select Address | 2-bit binary address selecting one of four framers for parallel port register access (00=framer 0, 11=framer 3) |
| CS*, RD*, WR* | Parallel Bus Control | Chip select, read strobe, and write strobe signals enabling standard microprocessor-style register read/write operations |
| JTMS/JTCK/JTDI/JTDO/JTRST | JTAG Boundary Scan | IEEE 1149.1 test access port pins supporting device-level debug, interconnect test, and in-system programming |
Key Features
| Feature | Design Value |
|---|---|
| Quad Independent E1 Framers | Four isolated framing engines-no shared resources-enabling concurrent E1 line termination with separate clock domains |
| Per-Channel Code Insertion | Programmable idle/code insertion in both TX and RX paths per DS0 channel, supporting drop-and-insert and conditioning applications |
| Hardware Signaling Reinsertion | Supports reinsertion of recovered CAS signaling onto backplane multiframe sync, eliminating software overhead in real-time systems |
| DS0 Monitoring Capability | Real-time monitoring of any single DS0 channel in both transmit and receive directions for diagnostics and performance validation |
| Extended Carrier Loss Detection | Configurable 1 ms carrier loss criteria per ETSI 300 233, improving robustness against transient noise in legacy infrastructure |
| Automatic RAI Generation | Complies with ETSI 300 011 by automatically generating Remote Alarm Indication when local alarms are detected |
Applications
| Access Multiplexer | TDM Switching Gateway |
|---|---|
|
Use Scenario: Aggregating multiple E1 lines from remote DSLAMs or base stations into a high-capacity STM-1 or IP backbone link. IC Role / Device Role / Timing Role: DS21Q44T acts as the E1 line interface framer, performing frame alignment, CAS extraction, and elastic store buffering before multiplexing. Use Value: Enables deterministic jitter management via dual elastic stores and ensures protocol-compliant signaling handoff to downstream ATM or packet processors. |
Use Scenario: Interfacing legacy TDM equipment (PBX, SS7 gateways) with modern VoIP or IMS core networks using TDM-over-IP gateways. IC Role / Device Role / Timing Role: DS21Q44T serves as the physical layer framer, recovering E1 timing, extracting channel-associated signaling, and presenting clean PCM data to the media gateway controller. Use Value: Maintains ETSI 300 011-compliant RAI generation and supports hardware-based signaling reinsertion-reducing CPU load and latency in real-time voice transport. |
| ISDN-PRI Concentrator | Carrier-Class Network Monitor |
|
Use Scenario: Consolidating up to four PRI circuits (each 30 B+D channels) for centralized call control in enterprise or service provider CPE. IC Role / Device Role / Timing Role: DS21Q44T performs PRI framing, D-channel HDLC processing (via integrated controller), and per-channel loopback for provisioning verification. Use Value: Leverages built-in 64-byte HDLC buffers and Sa-bit configuration to handle D-channel protocols without external logic, reducing BOM count and board area. |
Use Scenario: In-line passive monitoring of live E1 trunks in central offices to detect bit errors, framing slips, and alarm conditions without disrupting traffic. IC Role / Device Role / Timing Role: DS21Q44T operates in monitor mode-extracting FAS, CRC4, CAS, and bipolar violations while forwarding unmodified data through RLINK/TLINK paths. Use Value: Provides large on-chip counters for bipolar violations, CRC4 errors, FAS word errors, and E-bits-enabling long-term statistical analysis without host processor intervention. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad E1 framer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS21Q44TN | Same silicon, rated for -40°C to +85°C industrial temperature range; identical pinout, registers, and feature set | Required for outdoor cabinets, base station radios, or industrial environments exceeding 70°C ambient | Select DS21Q44TN when extended temperature operation is mandatory; otherwise DS21Q44T suffices for commercial indoor deployments. |
| DS21Q43 | Predecessor quad E1 framer; lacks HDLC controller, 8.192 MHz clock synthesizer, DS0 monitoring, and ETSI 300 233 carrier loss extension | Legacy designs where software compatibility is prioritized over new features; no hardware signaling reinsertion or Sa-bit HDLC support | DS21Q44T offers full backward register compatibility-existing DS21Q43 firmware runs unchanged-but adds critical enhancements for next-gen access systems. |
Compared with DS21Q44TN, the DS21Q44T trades extended temperature capability for lower cost and qualification scope in controlled environments; compared with DS21Q43, it delivers measurable improvements in signaling flexibility, diagnostic depth, and standards compliance-without requiring PCB or firmware redesign.
Availability
DS21Q44T is available at Aetrix Electronics and suitable for access multiplexers, TDM gateways, ISDN-PRI concentrators, and carrier-class network monitors requiring stable component supply, long-lifecycle support, and guaranteed traceability.
Supply support for DS21Q44T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and RF solutions for communications, industrial, and computing markets.
The DS21Q44T belongs to Maxim's telecom line interface product line, engineered specifically for E1/T1 framer applications in carrier infrastructure-emphasizing protocol compliance, low-jitter timing, and hardware-accelerated signaling processing.
FAQ
What is the operating temperature range for the DS21Q44T?
The DS21Q44T is specified for commercial operation from 0°C to +70°C. This range aligns with indoor telecom equipment deployments such as central office shelves, enterprise gateways, and managed service provider edge nodes. For extended environments, the DS21Q44TN variant supports -40°C to +85°C.
Does the DS21Q44T support both CAS and CCS signaling formats?
Yes, the DS21Q44T supports Frame Alignment Signal (FAS), Channel Associated Signaling (CAS), Common Channel Signaling (CCS), and CRC4 multiframe formats. Its flexible framing engine allows runtime selection per framer, enabling deployment in mixed-mode networks including legacy CAS-based PSTN and CCS-based SS7 interconnects.
How does the DS21Q44T handle elastic store synchronization with asynchronous backplanes?
The DS21Q44T uses dual two-frame elastic stores per framer, clocked by RSYSCLK (receive) and TSYSCLK (transmit) inputs. These stores absorb phase/frequency differences between the 2.048 MHz E1 data stream and backplane clocks up to 8.192 MHz-enabling reliable data transfer across clock domains without FIFO overflow or underflow.
Can the DS21Q44T perform per-channel loopback for testing?
Yes, the DS21Q44T supports per-channel loopback in both transmit and receive paths via programmable TCHBLK and RCHBLK outputs. These user-configurable channel block signals allow selective disabling of individual DS0 time slots-enabling targeted diagnostics, drop-and-insert validation, and field provisioning without affecting other active channels.
Is the DS21Q44T pin-compatible with earlier Maxim quad framers?
The DS21Q44T is pin-compatible with the DS21Q42 enhanced quad T1 framer only in mechanical footprint-not functional compatibility-due to differing E1 vs. T1 electrical and framing requirements. It is software-compatible with the DS21Q43, retaining identical register maps and control logic while adding new features.
DS21Q44T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 128-LQFP
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- -
- Interface:
- Parallel/Serial
- Number of Circuits:
- 4
- Voltage - Supply:
- 2.97V ~ 3.63V
- Current - Supply:
- 75mA
- Power (Watts):
- -
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 128-LQFP (14x20)
DS21Q44T FAQ
1.How can I place an order for DS21Q44T through Aetrix?
Please submit a Request for Quotation (RFQ) for DS21Q44T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for DS21Q44T reliable?
The price and inventory of DS21Q44T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS21Q44T is usually 5 days.
3.What payment methods are accepted for DS21Q44T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS21Q44T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DS21Q44T?
DS21Q44T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DS21Q44T order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for DS21Q44T?
For technical support, including DS21Q44T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS21Q44T requirements.
6.How does Aetrix verify that DS21Q44T is sourced from the original manufacturer or authorized distributors?
All DS21Q44T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that DS21Q44T meets industry standards.
7.What is the process for return or replacement of DS21Q44T?
All DS21Q44T units undergo pre-shipment inspection (PSI). If there is an issue with DS21Q44T, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The DS21Q44T part is unused and in its original packaging.
Return procedure for DS21Q44T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
DS21Q44T Tags
-
LMC567CMX/NOPB
Texas Instruments
-
LM567CMX/NOPB
Texas Instruments
-
LM567CM/NOPB
Texas Instruments
-
VSC8531XMW-02
Microchip Technology
-
VSC8531XMW-05
Microchip Technology
-
GPY115C0VI
MaxLinear, Inc.
-
SI32185-A-FMR
Skyworks Solutions Inc.
-
VSC8541XMV-05
Microchip Technology
-
SI32178-B-FM1R
Skyworks Solutions Inc.
-
GPY215C0VI
MaxLinear, Inc.
-
CPC7514ZTR
Littelfuse Inc.
-
VSC8502XML-03
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
