AD815AY - 500mA High-Speed Differential Driver | Analog Devices
MPN: AD815AY ✓ ActiveAD815AY Overview
A high-speed differential driver is a high-output-current amplifier stage used to transmit balanced signals through cables, transformers, or terminated analog lines. The AD815 family belongs to the broader hierarchy of differential amplifiers, line drivers, interface ICs, and analog semiconductors. Differential operation rejects common-mode noise, reduces radiated interference, and allows two signal polarities to be transmitted over one balanced connection when paired with a suitable receiver.
The AD815AY provides flexible configuration as either one differential driver or two independent single-ended drivers. According to the Analog Devices AD815 datasheet, each amplifier can supply at least 500 mA, with a minimum output drive of 400 mA per amplifier into a 10 Ω load. Differential output can reach 40 V p-p when powered from ±15 V supplies, while a coupling transformer with a turns ratio greater than 1:1 can support still higher output swing.
Signal-integrity performance is a defining feature of this device. The datasheet specifies low distortion of −66 dB at 1 MHz into a 200 Ω load with a 40 V p-p output, 120 MHz high-speed operation, and differential gain and phase matching of 0.05% and 0.45° into a 25 Ω load. These characteristics support accurate transmission of wideband analog signals without relying on an output stage built from separate discrete amplifiers.
Typical uses include analog video distribution, balanced communications, instrumentation, professional audio and video equipment, and high-current line-driving circuits. In a terminated video system, the AD815AY can drive back-terminated loads while preserving low distortion. Its current capability also makes it useful where a conventional low-power operational amplifier cannot drive the required load directly.
Layout and power-supply design are critical because high-speed, high-current outputs can expose trace resistance and supply impedance to amplifier gain. Keep output routing short, use low-inductance power connections, decouple each supply rail close to the device, and follow the pin assignments and output-load requirements in the manufacturer datasheet. Confirm thermal performance when operating continuously at maximum output current.
This product page combines manufacturer specifications, verified distribution data, drop-in-family comparison, and practical implementation guidance. The AD815AY should be selected specifically for high-current, high-speed balanced-output requirements, while a lower-current amplifier remains preferable when the load does not demand the AD815's drive capability.
Drop-in alternatives for AD815AY — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
AD815AYS
✅ Drop-In📋 Reference alternative (not in catalog)
AD815AYR7
✅ Drop-In📋 Reference alternative (not in catalog)
AD815AYRL
✅ Drop-In📋 Reference alternative (not in catalog)
AD815AY Maximum Ratings & Electrical Characteristics
| Device Type | Dual high-speed differential line driver |
| Amplifier Count | 2 amplifiers |
| Configuration | Differential driver or two single-ended drivers |
| Minimum Output Current | 500 mA per amplifier |
| Minimum Output Drive | 400 mA per amplifier into 10 ohm |
| Maximum Differential Output Voltage | 40 V p-p on ±15 V supplies |
| Bandwidth | 120 MHz |
| Harmonic Distortion | -66 dB at 1 MHz into 200 ohm with 40 V p-p output |
| Differential Gain Matching | 0.05% into 25 ohm |
| Differential Phase Matching | 0.45° into 25 ohm |
| Video Load Capability | 6 back-terminated video loads |
| Power Supply | ±15 V for 40 V p-p differential output |
| Package | 24-lead SOIC |
| Temperature Grade | Industrial temperature range |
| Output Configuration | Thermally enhanced differential and single-ended outputs |
| ADSL Output Power | 26 dBm differential line drive |
AD815AY 24-lead soic Pin Configuration Guide
Pin configuration for AD815AY (24-lead soic package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for AD815AY.
Refer to the datasheet for full pin configuration.
Typical Applications
AD815AY is suitable for 6 applications: Back-Terminated Video Distribution, Balanced Communications Line Driver, Professional Video Output Amplifier, High-Output Instrumentation Driver, Audio and Low-Frequency Power Buffer, Transformer-Coupled Transmitter Output.
Back-Terminated Video Distribution
The AD815AY is well suited to driving balanced or back-terminated video lines because the Analog Devices AD815 datasheet specifies six back-terminated video loads and 120 MHz bandwidth. Each amplifier can supply at least 500 mA, allowing the device to support substantial source and termination currents without relying on a low-current operational amplifier. Its low distortion of −66 dB at 1 MHz into 200 Ω helps preserve signal fidelity. The driver should be configured according to the manufacturer's recommended network, with short output traces, controlled source impedance, and terminations matched to the cable. Verify settling behavior and output compliance for the specific video standard.
Recommended
Balanced Communications Line Driver
AD815AY can serve as the output stage for balanced communications equipment that combines high bandwidth with substantial line current. The 120 MHz rated speed supports wideband signal paths, while the 500 mA minimum output current per amplifier provides margin for transformer and cable loading. Differential operation also reduces common-mode noise pickup and can lower radiated interference when the transmitter and receiver impedances are properly matched. Transformer turns ratio, termination resistance, and allowable output power determine the usable swing. Confirm supply headroom and isolation from the receive path to prevent signal leakage.
Recommended
Professional Video Output Amplifier
The AD815AY provides the drive current and bandwidth required for professional analog-video output stages feeding terminated lines. Its differential configuration supports a 40 V p-p output on ±15 V supplies, and the specified −66 dB distortion at 1 MHz into 200 Ω limits added nonlinearity. The dual-amplifier arrangement can also be used for separate single-ended outputs when the circuit does not require a balanced topology. Maintain adequate output-voltage headroom, use controlled impedance routing, and verify settling time against the video bandwidth. Thermal analysis is essential at sustained high output current.
Recommended
High-Output Instrumentation Driver
AD815AY fits instrumentation paths that need to drive low-impedance or terminated analog inputs without sacrificing wideband response. The 120 MHz bandwidth, 500 mA minimum output current, and 0.05% differential gain matching into 25 Ω support precise signal transfer across the driver pair. Differential gain and phase matching are particularly important when both outputs contribute to downstream calibration or conversion. Place output components and feedback networks to maintain the datasheet performance, and verify that the instrumentation amplifier or ADC input presents a load compatible with the driver's output-current capability.
Recommended
Audio and Low-Frequency Power Buffer
Although optimized for high-speed differential operation, AD815AY can serve as a high-current buffer in audio or other low-frequency balanced output stages. Its minimum 500 mA per-amplifier output current provides more load capability than many precision operational amplifiers, while differential operation can suppress even-order distortion and reject common-mode noise. The ±15 V supply arrangement supports a 40 V p-p differential output, but sustained operation at large output current can generate substantial heat. Use adequate copper area, observe thermal limits, and select suitable output protection appropriate to the load.
Recommended
Transformer-Coupled Transmitter Output
The AD815AY is suitable for transformer-coupled transmitter outputs where high current, low distortion, and flexible configuration are important. The Analog Devices AD815 datasheet notes that a coupling transformer with a turns ratio greater than 1:1 can increase output swing beyond the direct 40 V p-p differential capability available on ±15 V supplies. The dual amplifiers can also be arranged as independent single-ended drivers when the transformer or load topology requires separate outputs. Transformer leakage inductance, core nonlinearity, winding resistance, and load reflection must be evaluated together because the driver's high bandwidth can expose poor matching.
Recommended
Recommended Products Summary
Engineering reference data for AD815AY — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD815AYS | AD815AYR7 | AD815AYRL |
|---|---|---|---|---|
| Package | 24-lead SOIC | 24-lead SOIC | 24-lead SOIC | 24-lead SOIC |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
Key Differentiators
- High output-current capability (vs AD815AYS)
- Wideband differential output operation (vs AD815AYR7)
- Low distortion into terminated analog loads (vs AD815AYRL)
Design Notes
The AD815AY can dissipate substantial heat when driving low-impedance loads at high output current. Use the manufacturer thermal characterization for the exact package and board environment, and provide as much PCB copper as practical around the package. Estimated: with 7 W dissipated and a junction-to-ambient resistance of 30 C/W, the calculated junction-temperature rise is 210 C before ambient is added; verify this estimate against the datasheet thermal model and actual PCB construction.
Route each high-current output as a short, direct path with minimal vias and generous copper width. Long or narrow traces add series resistance, limiting output swing and increasing heating, while loop area can couple output current into sensitive input circuitry. Place output feedback and balancing components close to the device, and use a low-inductance ground return for the amplifier outputs.
Decouple both supply rails close to the AD815AY pins and use components with suitable voltage rating and effective high-frequency behavior. The device can demand 500 mA per amplifier, so the supply, traces, and connectors must support peak and sustained current without voltage collapse. Keep switching-regulator loops away from the outputs and verify that supply bypassing does not create unwanted feedback through shared ground impedance.
Do not assume that matching package names establish a valid drop-in substitution. Confirm every pin, exposed-pad connection, supply limit, output-current rating, thermal rating, and ordering option against the manufacturer datasheet. Also avoid operating at the output-current or output-voltage limit without confirming the junction temperature. The AD815's high bandwidth can expose incorrect feedback layouts, excessive load capacitance, and poorly terminated cables as ringing or instability.
Compliance Information
The available manufacturer and distributor information identifies the AD815 as an industrial-temperature-range high-output-current differential driver but does not explicitly state the requested compliance classifications.
