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Analog Devices Inc./Maxim Integrated DS1021S-25+
- Part No.:
- DS1021S-25+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Delay Lines
- Package:
- 16-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
DS1021S-25+.pdf
- Description:
- IC DEL LN 256TAP 73.75NS 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,669
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Product details
Overview
DS1021S-25+ from Maxim Integrated (formerly Dallas Semiconductor) is a programmable 8-bit all-silicon delay line IC used for precise digital timing adjustment in high-speed logic systems. It delivers 0.25 ns incremental delay steps, 10 ns inherent step-zero delay, and maximum 73.75 ns total delay with rising/falling edge accuracy. It supports both 3-wire serial and 8-bit parallel programming and drives up to 10 LS-TTL loads.
For engineers reviewing the DS1021S-25+ datasheet, DS1021S-25+ pinout, DS1021S-25+ application, or DS1021S-25+ equivalent, key selection considerations include its 16-pin SOIC package, 5 V CMOS/TTL compatibility, dual programming interface flexibility, and nanosecond-level edge-aligned delay reproducibility in test instrumentation and clock skew compensation circuits.
Technical Context
The DS1021S-25+ implements a fully CMOS-based tapped delay chain architecture with user-programmable tap selection via 8-bit register. Delay resolution is fixed at 0.25 ns per step across all 256 settings, with inherent 10 ns base delay independent of programming. Both input edges are delayed identically, enabling true non-inverting, edge-accurate signal translation.
Programming is supported in two mutually exclusive modes: parallel mode (S = 1) uses P0–P7 as static binary inputs with E as latch enable, while serial mode (S = 0) shifts data MSB-first via D/C/Q pins with E controlling register activation. Daisy-chaining is enabled by Q-to-D interconnection between devices.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Delay Resolution | 0.25 ns per step - enables fine-grained timing alignment in high-speed digital interfaces |
| Max Total Delay | 73.75 ns - covers critical setup/hold window adjustments in 100+ MHz logic |
| Step-Zero Delay | 10.00 ns ±2 ns - fixed propagation baseline unaffected by programming state |
| Supply Voltage | 4.75 V to 5.25 V - compatible with standard 5 V TTL/CMOS logic rails |
| Output Drive | Drives 10 × 74LS loads - sufficient fanout for multi-receiver timing distribution |
| Edge Accuracy | Rising & falling edge matched within ±6 ns - ensures deterministic pulse width preservation |
| Serial Clock Max | 10 MHz - supports fast reprogramming without external timing overhead |
Pinout & Package
DS1021S-25+ is housed in a low-profile, surface-mount 16-pin SOIC (300-mil) package, auto-insertable and compatible with vapor phase, IR, and wave soldering processes.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN | Delay Input | Primary signal path entry; accepts TTL/CMOS-compatible logic levels |
| OUT | Delay Output | Non-inverted, edge-accurate replica of IN after programmed delay |
| P0–P7 | Parallel Program Inputs | 8-bit binary word defining delay value in parallel mode (S = 1) |
| S | Mode Select | High = parallel mode; Low = serial mode - configures interface behavior at power-up |
| E | Enable | Latches parallel data or activates serial register load; must be high during programming |
| C | Serial Clock | MSB-first shift clock for serial programming and readback |
| D | Serial Data Input | Accepts 8-bit delay setting in serial mode; requires defined logic level when unused |
| Q | Serial Data Output | Shifts out current register contents MSB-first; intended for daisy-chain or readback |
| VCC | Power Supply | +5 V supply; decoupling recommended near pin for noise-sensitive timing |
| GND | Ground | Reference return for all signals and supply; low-impedance connection required |
Key Features
| Feature | Design Value |
|---|---|
| All-silicon construction | Eliminates hybrid packaging reliability risks and enables consistent wafer-level process control |
| Dual programming interface | Supports both static jumper/DIP-switch configuration and dynamic microcontroller-driven reprogramming |
| Daisy-chain capability | Enables synchronized delay tuning across multiple DS1021S-25+ units using single serial bus |
| Edge-accurate delay | Maintains identical tPLH and tPHL values - preserves pulse width integrity in clock/data paths |
| Low-power CMOS design | Typical active current 30 mA at 1 µs period - suitable for dense timing arrays with thermal constraints |
Applications
| Test Equipment Timing Calibration | Digital Logic Skew Compensation |
|---|---|
Use Scenario: Precise alignment of stimulus and response channels in automated test equipment (ATE) for semiconductor validation. IC Role / Device Role / Timing Role: Programmable delay element inserted in reference clock or trigger path to calibrate channel-to-channel timing offsets. Use Value: 0.25 ns resolution enables sub-cycle alignment of 4 GHz-equivalent sampling windows, improving measurement repeatability. | Use Scenario: Matching propagation delays across parallel data buses in FPGA-to-ASIC interfaces or memory controllers. IC Role / Device Role / Timing Role: Inserted on individual data or strobe lines to equalize flight time and meet setup/hold timing budgets. Use Value: Step-zero 10 ns base delay plus 0.25 ns granularity allows fine-tuning without adding excessive latency. |
| Programmable Clock Deskew | Logic Analyzer Trigger Conditioning |
Use Scenario: Dynamic deskewing of clock domains in multi-FPGA systems where board layout asymmetry causes skew. IC Role / Device Role / Timing Role: Configurable delay on clock distribution branches to realign synchronous domains before fanout buffers. Use Value: Serial reprogramming allows runtime skew correction without hardware modification or FPGA reconfiguration. | Use Scenario: Shaping trigger timing relative to acquisition windows in high-bandwidth logic analyzers. IC Role / Device Role / Timing Role: Adjustable delay on external trigger input to position trigger point precisely within captured waveform buffer. Use Value: 73.75 ns max delay covers full acquisition window alignment needs for 10+ ns sample periods. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar programmable delay line applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS1021S-50+ | 0.5 ns step size, 137.5 ns max delay, same 10 ns base delay and pinout | Better suited for lower-frequency systems requiring coarser but wider-range delay tuning | Select DS1021S-50+ when 0.25 ns resolution is unnecessary and extended range improves margin in jitter-prone environments |
| ON Semiconductor MC100EP195MNR4G | Differential ECL/PECL interface, 3.3 V supply, 0.1 ns resolution, 2.2 ns min delay | Requires level-shifting for 5 V TTL/CMOS systems; optimized for RF and high-speed serial links | Choose MC100EP195MNR4G only when interfacing with differential signaling standards and sub-0.25 ns precision is required |
Compared with DS1021S-50+ and MC100EP195MNR4G, DS1021S-25+ uniquely balances 5 V single-ended compatibility, 0.25 ns resolution, and ease of microcontroller-based serial reconfiguration - making it optimal for embedded test fixtures and industrial logic timing where cost, voltage compatibility, and moderate precision converge.
Availability
DS1021S-25+ is available at Aetrix Electronics and suitable for test instrumentation, digital logic timing calibration, and clock deskew applications requiring stable component supply and long-term obsolescence management.
Supply support for DS1021S-25+ 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 (acquired by Analog Devices in 2021) designs precision analog, mixed-signal, and timing ICs for industrial, communications, and computing markets.
The DS1021S-25+ belongs to Maxim's legacy silicon delay line product line, engineered specifically to replace hybrid delay modules with monolithic, programmable, and solder-reflow-compatible alternatives for high-reliability timing control.
FAQ
What is the inherent delay of DS1021S-25+ at step zero?
The DS1021S-25+ has a guaranteed inherent delay of 10.00 ns ±2 ns at step zero, independent of programming mode or supply conditions. This base delay is present even when P0–P7 are all low or serial register is loaded with 0x00. It represents the minimum propagation time through the internal delay chain and is measured between 1.5 V points on input and output edges under standard test conditions (VCC = 5.0 V, TA = 25°C).
Can DS1021S-25+ be used with 3.3 V logic systems?
No, DS1021S-25+ is specified only for 5 V operation (4.75 V to 5.25 V). Its VIH minimum is 2.2 V and VIL maximum is 0.8 V, which do not guarantee reliable interfacing with 3.3 V CMOS logic without level translation. Driving DS1021S-25+ inputs from 3.3 V sources may result in marginal noise margins or undefined behavior. For 3.3 V systems, consider alternatives like the ON Semiconductor MC100EP195MNR4G or dedicated low-voltage delay ICs.
How does serial readback work on DS1021S-25+?
Serial readback on DS1021S-25+ is destructive: reading the current 8-bit delay value shifts it out MSB-first on the Q pin while clearing the register. To restore the value, a 1 kΩ–10 kΩ resistor must connect Q to D. The process requires eight clock cycles with E held high and C toggled, after which the original value is rewritten. If restoration completes before E returns low, no settling time (tEDV) is needed - the DS1021S-25+ continues operating with unchanged delay.
Is DS1021S-25+ pin-compatible with DS1021S-50+?
Yes, DS1021S-25+ and DS1021S-50+ share identical 16-pin SOIC packaging, pin assignments, electrical interface definitions, and functional block architecture. They differ only in internal delay cell design - resulting in different step sizes (0.25 ns vs. 0.5 ns) and maximum delays (73.75 ns vs. 137.5 ns). No PCB layout change is required when substituting between these variants, though firmware or hardware programming logic must account for the different scaling factor.
What is the maximum clock frequency supported for serial programming of DS1021S-25+?
The DS1021S-25+ supports a maximum serial clock (C) frequency of 10 MHz, as specified in its AC Electrical Characteristics table. This allows full 8-bit register load or readback in ≤800 ns. Timing requirements including tDSC (30 ns), tDHC (10 ns), and tES/tEH (50 ns each) must be met. Exceeding 10 MHz may cause metastability or incorrect bit capture, especially under worst-case temperature and voltage conditions.
DS1021S-25+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 16-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Number of Taps/Steps:
- 256
- Function:
- Programmable
- Delay to 1st Tap:
- 10ns
- Tap Increment:
- 250 ps
- Available Total Delays:
- 73.75ns
- Number of Independent Delays:
- 1
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
DS1021S-25+ FAQ
1.How can I place an order for DS1021S-25+ through Aetrix?
Please submit a Request for Quotation (RFQ) for DS1021S-25+ 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 DS1021S-25+ reliable?
The price and inventory of DS1021S-25+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS1021S-25+ is usually 5 days.
3.What payment methods are accepted for DS1021S-25+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS1021S-25+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DS1021S-25+?
DS1021S-25+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DS1021S-25+ 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 DS1021S-25+?
For technical support, including DS1021S-25+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS1021S-25+ requirements.
6.How does Aetrix verify that DS1021S-25+ is sourced from the original manufacturer or authorized distributors?
All DS1021S-25+ 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 DS1021S-25+ meets industry standards.
7.What is the process for return or replacement of DS1021S-25+?
All DS1021S-25+ units undergo pre-shipment inspection (PSI). If there is an issue with DS1021S-25+, 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 DS1021S-25+ part is unused and in its original packaging.
Return procedure for DS1021S-25+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
DS1021S-25+ Tags
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