ALD  -  Series DataSheet
ALD1108xx  -  ALD1108xx Performance PERFORMANCE CHARACTERISTICS OF EPAD? MATCHED PAIR MOSFET ARRAYS  -  Advanced Linear Devices  -  Drivers MOSFET-IGBT Drivers

GENERAL DESCRIPTION
ALD1108xx/ALD1109xx/ALD1148xx/ALD1149xx are monolithic quad/dual N-Channel MOSFETs matched at the factory using ALD’s proven EPAD® CMOS technology. These devices are intended for low voltage, small signal applications.
This EPAD MOSFET Array product family (EPAD MOSFET) is available in the three separate categories, each providing a distinctly different set of device electrical specifications and characteristics. The first category is the ALD110800/ALD110900 zero-threshold mode EPAD MOSFETs. The second category is the ALD1108xx/ALD1109xx enhancement mode EPAD MOSFETs. The third category is the ALD1148xx/ALD1149xx depletion mode EPAD MOSFETs. (The suffix “xx” denotes threshold voltage in 0.0 V steps, for example, xx=08 denotes 0.8V).
The ALD110800/ALD110900 (quad/dual) are EPAD MOSFETs in which the individual threshold voltage of each MOSFET is fixed at zero. The threshold voltage is defined as Ids =1uA @ Vds=0.1V when the gate voltage Vgs = 0.0V. Zero threshold devices operate in the enhancement region when operated above threshold voltage and current level (Vgs>0.0V and Ids>1 uA) and subthreshold region when operated at or below threshold voltage and current level (Vgs<=0.0V and Ids<1 uA). This device, along with other very low threshold voltage members of the product family, constitute a class of EPAD MOSFETs that enable ultra low supply voltage operation and nanopower type of circuit designs, applicable in either analog or digital circuits.
The ALD1108xx/ALD1109xx (quad/dual) product family features precision matched enhancement mode EPAD MOSFET devices, which require a positive bias voltage to turn on. Precision threshold values such as +1.40V, +0.80V, +0.20V are offered. No conductive channel exists between the source and drain at zero applied gate voltage for these devices, except that the +0.20V version has a subthreshold current at about 20 nA.
The ALD1148xx/ALD1149xx (quad/dual) features depletion mode EPAD MOSFETs, which are normally-on devices when the gate bias voltage is at zero volt. The depletion mode threshold voltage is at a negative voltage level at which the EPAD MOSFET turns off. Without a supply voltage and/ or with Vg=0.0V the EPAD MOSFET device is already turned on and exhibits a defined and controlled on-resistance between the source and drain terminals.
The ALD1148xx/ALD1149xx depletion mode EPAD MOSFETs are different from most other types of depletion mode MOSFETs and certain types of JFETs in that they do not exhibit high gate leakage currents and channel/ junction leakage currents. When negative signal voltages are applied to the gate terminal, the designer/user can depend on the EPAD MOSFET device to be controlled, modulated and turned off precisely. The device can be modulated and turned-off under the control of the gate voltage in the same manner as the enhancement mode EPAD MOSFET and the same device equations apply.
EPAD MOSFETs are designed for exceptional device electrical characteristics matching. As these devices are on the same monolithic chip, they also exhibit excellent tempco tracking characteristics. Besides matched pair electrical characteristics, each individual EPAD MOSFET also exhibits tightly controlled parameters, enabling the user to depend on design limits. Even units from different batches have well matched characteristics.