Advanced Linear Devices ALD114835PCL

The ALD114835/ALD114935 are high-precision monolithic quad/dual depletion-mode N-channel MOSFETs, matched at the factory using ALD's proven EPAD CMOS technology. These devices are designed for low-voltage, small-signal applications. They serve as an excellent functional replacement for normally-closed relay applications, as they are in the on-state when no power is applied, but can be turned off or modulated when system power is enabled. These MOSFETs feature unique characteristics: with the gate grounded, they operate in resistive mode at low drain voltages and in current-source mode at higher voltages, providing a constant drain current.

The ALD114835/ALD114935 MOSFETs are carefully designed for excellent device electrical parameter matching. Since these devices are integrated on the same monolithic die, they also exhibit superior temperature tracking characteristics. They are highly versatile and serve as fundamental building blocks for a wide range of analog applications, including current sources, differential amplifier input stages, transmission gates, and multiplexer applications. In addition to the matched electrical characteristics of the paired devices, each individual MOSFET also features well-controlled parametric specifications, allowing users to rely on tight design constraints. Even across different production lots and manufacturing dates, consistently well-matched characteristics are maintained.

These depletion-mode devices are designed to achieve minimum offset voltage and differential thermal response, suitable for switching and amplification applications in 5V to ±5V single-supply systems where low input bias current, low input capacitance, and fast switching speed are desirable. These devices feature well-controlled turn-off and subthreshold characteristics, making them suitable for designs that rely on subthreshold behavior.

The ALD114835/ALD114935 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 highest positive voltage in the system and the V- and IC pins to the lowest negative voltage. The voltages on all other pins must always remain within these voltage limits.

• Depletion-mode (normally-on)
• Precise gate threshold voltage: -3.50V ± 0.05V
• Nominal RDS(ON) of 540Ω at VGS = 0.0V
• Matched characteristics between MOSFETs
• Tight lot-to-lot parameter control
• Low input capacitance
• VGS(th) matching (VOS) — 20mV
• High input impedance — typical 10^12Ω
• 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
• Zero-power fail-safe circuits
• Backup battery circuits
• Power failure detectors
• Fail-safe signal detectors
• Source followers and buffers
• Precision current mirrors
• Precision current sources
• Capacitive probes
• Sensor interfaces
• Charge detectors
• Charge integrators
• Differential amplifier input stages
• High-side switches
• Peak detectors
• Sample-and-hold circuits
• Alarm systems
• Current multipliers
• Analog switches
• Analog multiplexers
• Voltage comparators
• Level translators