ADG719BRTZ-REEL7 is a low-voltage, low-on-resistance, single-pole double-throw (SPDT) analog switch designed and manufactured by Analog Devices Inc. (ADI). It belongs to the high-performance ADG71x family, engineered specifically for precision, low-power, and space-constrained signal routing applications, where minimal signal distortion, fast switching, rail-to-rail operation, and compatibility with low-voltage logic (e.g., 1.8 V, 2.5 V, 3.3 V) are critical.
The “BRTZ” suffix denotes the 6-lead SOT-23 package (2.9 mm × 1.6 mm) — one of the smallest standard surface-mount packages available; the “-REEL7” indicates 7-inch tape-and-reel packaging (3,000 units per reel), Pb-free, RoHS-compliant, and qualified for industrial operation (–40°C to +85°C ambient, or –40°C to +125°C junction).
⚠️ Critical Clarification:
The ADG719 is not a general-purpose CMOS switch. It is a precision, low-distortion, low-leakage analog switch, optimized for:
- Ultra-low on-resistance (RON): 2.5 Ω (typ.) at VDD = 3 V, with flatness < 0.5 Ω — preserves gain accuracy and minimizes insertion loss in sensor multiplexing and PGA front-ends;
- Low charge injection: 0.3 pC (typ.), enabling use in sampling circuits (e.g., sample-and-hold, ADC input muxes) without significant kickback error;
- Near-zero leakage current: ±10 pA (max) at 25°C, < ±100 pA over temperature — essential for high-impedance sensor interfaces (e.g., pH electrodes, piezoelectric sensors) and precision integrators;
- Rail-to-rail analog signal handling: Supports signals from VSS to VDD, even with supply as low as 1.8 V, making it ideal for modern ultra-low-power microcontrollers and battery-powered systems.
It operates from a single 1.8 V to 5.5 V supply, consumes only < 1 nA quiescent current, and features robust protection: ESD > 2 kV HBM, overvoltage tolerance (±5 V on I/O pins), and break-before-make switching action — ensuring no momentary short between signal paths.
Introduction
The ADG719BRTZ-REEL7 delivers exceptional analog switching performance in a microscopic footprint:
🔹 Minimal signal degradation: With RON = 2.5 Ω (typ.) and RON flatness < 0.5 Ω, it introduces < 0.05% gain error in a 5 kΩ source impedance path — far superior to typical SPDT switches (>10 Ω);
🔹 Ultra-low distortion & noise: THD < −100 dB @ 1 kHz (1 kΩ load), 1.5 nV/√Hz output noise — preserves fidelity in audio, sensor, and instrumentation signal chains;
🔹 Fast, clean switching: Turn-on time = 12 ns, turn-off time = 8 ns, with < 1 ns channel-to-channel skew — suitable for high-speed multiplexing and time-division systems;
🔹 True low-voltage operation: Fully specified down to 1.8 V supply, with logic-compatible control inputs (no level shifters needed for 1.8 V GPIOs).
Its SOT-23-6 (BRTZ) package (2.9 mm × 1.6 mm) features an exposed pad for thermal enhancement — enabling full 2.5 Ω performance even in high-temperature environments when properly laid out. With only two external components required (VDD decoupling cap + optional logic pull-down), it replaces bulky mechanical relays or discrete MOSFET arrays, reducing board space, power, and failure risk.
Key Features
✅ Precision Analog Switching Core:
• Configuration: Single-Pole Double-Throw (SPDT) — one common (COM), two throws (NO/NC);
• On-resistance (RON): 2.5 Ω (typ.) @ VDD = 3 V, < 4 Ω (max) over temp/voltage;
• RON flatness: < 0.5 Ω (typ.), critical for THD and linearity;
• Charge injection: 0.3 pC (typ.), < 1 pC (max) — enables accurate sampling without hold capacitor corruption.
✅ Ultra-Low Power & Compact Size:
• Supply voltage: 1.8 V to 5.5 V;
• Quiescent current: < 1 nA (typ.), < 10 nA (max);
• Package: 6-lead SOT-23 (2.9 mm × 1.6 mm) with exposed pad (BRTZ) — smallest precision SPDT in its class;
• Operating temperature: –40°C to +125°C junction.
✅ High Performance & Robustness:
• Bandwidth: 200 MHz (−3 dB) — supports video, ultrasound, and RF signal routing;
• THD: < –100 dB @ 1 kHz (1 kΩ load);
• Leakage current: ±10 pA (max) @ 25°C, < ±100 pA @ 85°C;
• Overvoltage protection: ±5 V on COM/NO/NC pins (beyond supply rails).
✅ Simple Control Interface:
• Digital control: single active-high EN pin — logic thresholds scale with VDD;
• No external level shifters needed — fully compatible with 1.8 V, 2.5 V, 3.3 V, and 5 V microcontrollers;
• Break-before-make switching: ensures no overlap between NO and NC paths.
✅ Low-Voltage Optimized Operation:
• Guaranteed operation down to 1.8 V supply, with RON = 4.5 Ω (max) — unlike many switches that degrade significantly below 3 V;
• Logic-compatible inputs: VIL = 0.3×VDD, VIH = 0.7×VDD — eliminates need for external logic translators.
Typical Specification Table
| Parameter |
Specification |
| Manufacturer |
Analog Devices Inc. (ADI) |
| Product Series |
ADG71x Family (Low-Voltage Precision Analog Switches) |
| Model |
ADG719BRTZ-REEL7 |
| Function |
Single-Pole Double-Throw (SPDT) Analog Switch |
| On-Resistance (RON) |
2.5 Ω (typ.) @ 3 V, < 4 Ω (max) over temp/voltage |
| RON Flatness |
< 0.5 Ω (typ.) |
| Charge Injection |
0.3 pC (typ.), < 1 pC (max) |
| Leakage Current (25°C) |
±10 pA (max) |
| Bandwidth (–3 dB) |
200 MHz |
| THD @ 1 kHz (1 kΩ) |
< –100 dB |
| Supply Voltage |
1.8 V to 5.5 V |
| Quiescent Current |
< 1 nA (typ.), < 10 nA (max) |
| Switching Time (tON/tOFF) |
12 ns / 8 ns |
| Control Interface |
Active-high EN (logic-level compatible) |
| Package |
6-Lead SOT-23 (2.9 mm × 1.6 mm) with Exposed Pad (BRTZ) |
| RoHS / Green |
Yes (Pb-free, Halogen-free) |
| Packaging |
7-inch Reel, 3,000 units (REEL7) |
Typical Applications
🔹 Precision Sensor Multiplexing: Routing multiple high-impedance sensors (e.g., thermocouples, RTDs, pH electrodes) to a single precision ADC — leveraging low leakage (<10 pA) and low RON to avoid measurement errors and drift.
🔹 Programmable Gain Amplifier (PGA) Front-Ends: Selecting feedback resistors or input attenuators in multi-range instrumentation amplifiers — using low RON flatness to maintain gain accuracy across channels.
🔹 Battery-Powered & Portable Devices: Wearables, handheld meters, and IoT edge nodes — enabled by 1.8 V operation, <1 nA quiescent current, and SOT-23 size.
🔹 Audio Signal Routing: Headphone jack detection, microphone selection, and stereo channel switching in smartphones and hearables — benefiting from low THD and rail-to-rail operation.
🔹 Medical Instrumentation: EEG/ECG lead selection, disposable sensor interface switching, and portable diagnostic devices — where low charge injection prevents baseline shift and artifact generation.
🔹 Industrial Process Control: Modular I/O systems, distributed temperature/humidity loggers, and PLC analog input modules — using robust overvoltage protection (±5 V) for field reliability.
Development & Design Notes
🔧 PCB Layout Best Practices:
- Use a solid ground plane beneath the SOT-23 — connect the exposed pad (EP) to it with ≥ 4 thermal vias (0.25 mm) to improve thermal stability and reduce noise coupling.
- Keep analog traces (COM, NO, NC) short and symmetric — avoid crossing digital lines (e.g., EN) — use ground guard rings if routing density is high.
- Avoid placing the switch near heat sources (e.g., power inductors) — its leakage doubles every ～10°C rise; keep ambient < +60°C for <50 pA leakage.
🔧 Power Supply Decoupling:
- Place a 100 nF X7R ceramic capacitor within 1 mm of VDD and GND pins — critical for clean switching and low-noise performance.
- For best THD in audio applications, add a 10 µF tantalum capacitor near the power entry point — improves low-frequency PSRR.
🔧 Control Interface & Firmware Integration:
- Tie EN directly to a microcontroller GPIO — no pull-up/down resistors needed (internal logic thresholds scale with VDD).
- Use hardware debouncing or firmware delay (～100 ns) after asserting EN before sampling — avoids transient glitches during switching.
- For fail-safe operation, assert EN only during known stable periods (e.g., between ADC conversions) — prevents corruption of sampled data.
🔧 Thermal Management & Reliability:
- The SOT-23 has no large thermal pad — θJA ≈ 250°C/W. For continuous operation above +50°C ambient, ensure ≥ 25 mm² copper pour under the IC and use forced airflow.
- FIT rate = 28 failures per billion hours, with FMEDA report supporting IEC 61508 SIL-2 — combine periodic self-test (e.g., measure RON via known current source) for functional safety compliance.
🔧 Calibration & Accuracy Optimization:
- For metrology-grade applications, perform one-time factory calibration of RON vs. temperature — ADI provides typical RON vs. VDD/temp curves in datasheet.
- To minimize THD in audio paths, use matched external series resistors (e.g., 10 Ω) on COM/NO/NC — balances capacitive mismatch and improves linearity.
