Advanced Linear Devices ALD114904SAL

ALD114804A/ALD114804/ALD114904A/ALD114904 are high-precision monolithic quad/dual depletion-mode N-channel MOSFETs, factory-matched using ALD's proven EPAD® CMOS technology. These devices are suited for low-voltage, small-signal applications. They serve as ideal functional replacements for normally-closed relay applications, as they are in a normally-on (conducting) state when no power is applied, yet can be turned off or modulated when system power is enabled. These MOSFETs exhibit unique characteristics: with the gate grounded, they operate in resistive mode at low drain voltage levels and in current source mode at higher voltage levels, providing a constant drain current.

The ALD114804A/ALD114804/ALD114904A/ALD114904 MOSFETs are designed for excellent device electrical characteristics matching. Since these devices reside on the same monolithic die, they also exhibit outstanding temperature tracking characteristics. They serve as design building blocks for a wide range of analog applications, such as current sources, differential amplifier input stages, transmission gates, and multiplexer applications. In addition to the matched-pair electrical characteristics, each individual MOSFET also features well-controlled parameters, enabling users to rely on tight design constraints corresponding to well-matched characteristics.

These depletion-mode devices are designed for minimum offset voltage and differential thermal response, for switching and amplification applications in single-supply (0.4V to +5V) or dual-supply (+/-0.4V to +/-5V) systems requiring low input bias current, low input capacitance, and fast switching speed. These devices feature well-controlled turn-off and subthreshold characteristics, making them suitable for designs that depend on subthreshold behavior.

The ALD114804A/ALD114804/ALD114904A/ALD114904 are suited for precision applications requiring very high current gain β, such as current mirrors and current sources. At 25°C, with a drain current of 3mA and an input leakage current of 30pA, an example DC current gain calculation yields 3mA / 30pA = 100,000,000. For most applications, connect the V+ pin to the most positive voltage in the system, and the V- and IC pins to the most negative voltage in the system. The voltages on all other pins must always remain within these voltage limits.

• Depletion-mode (normally-on)
• Precise gate threshold voltage: -0.40V +/-0.02V
• Nominal RDS(ON) of 5.4 KΩ at VGS = 0.0V
• Matched MOSFET characteristics
• Tight lot-to-lot parameter control
• Low input capacitance
• VGS(th) matching (VOS) - 20 mV
• High input impedance — typical 10^12 Ω
• Positive, zero, and negative VGS(th) temperature coefficients
• DC current gain >10^8
• Low input and output leakage current

• Functional replacement for type-B (normally closed) relays
• Ultra-low power (nanoamp) analog and digital circuits
• Ultra-low operating voltage (<0.2V) analog and digital circuits
• Sub-threshold biasing and operating circuits
• Zero-power fail-safe circuits in alarm systems
• Backup battery circuits
• Power failure and fail-safe detectors
• Source followers and high-impedance buffers
• Precision current mirrors and current sources
• Capacitive probe and sensor interfaces
• Charge detectors and charge integrators
• Differential amplifier input stages
• High-side switches
• Peak detectors and level translators
• Sample-and-hold
• Current multipliers
• Discrete analog switches and multiplexers
• Discrete voltage comparators