A
DVANCED
L
INEAR
D
EVICES,
I
NC.
ALD212900/ALD212900A
PRECISION N-CHANNEL EPAD
®
MOSFET ARRAY
DUAL HIGH DRIVE ZERO THRESHOLD™ MATCHED PAIR
e
TM
EPAD
E
N
®
AB
LE
D
VGS(th)= +0.00V
GENERAL DESCRIPTION
ALD212900A/ALD212900 precision N-Channel EPAD
®
MOSFET array is preci-
sion matched at the factory using ALD’s proven EPAD
®
CMOS technology. These
dual monolithic devices are enhanced additions to the ALD110900A/ALD110900
EPAD
®
MOSFET Family, with increased forward transconductance and output
conductance, particularly at very low supply voltages.
Intended for low voltage, low power small signal applications, the ALD212900A/
ALD212900 features Zero-Threshold™ voltage, which enables circuit designs
with input/output signals referenced to GND at enhanced operating voltage
ranges. With these devices, a circuit with multiple cascading stages can be
built to operate at extremely low supply/bias voltage levels. For example, a
nanopower input amplifier stage operating at <0.2V supply voltage has been
successfully built with these devices.
ALD212900A/ALD212900 EPAD MOSFETs feature exceptional matched pair
device electrical characteristics of Gate Threshold Voltage V
GS(th)
set precisely
at +0.00V +0.01V, I
DS
= +20µA @ V
DS
= 0.1V, with a typical offset voltage of
only +/- 0.001V (1mV). Built on a single monolithic chip, they also exhibit excel-
lent temperature tracking characteristics. These precision devices are versatile
as design components for a broad range of analog small signal applications
such as basic building blocks for current mirrors, matching circuits, current
sources, differential amplifier input stages, transmission gates, and multiplex-
ers. They also excel in limited operating voltage applications, such as very low
level voltage-clamps and nano-power normally-on circuits.
In addition to precision matched-pair electrical characteristics, each individual
EPAD MOSFET also exhibits well controlled manufacturing characteristics, en-
abling the user to depend on tight design limits from different production batches.
These devices are built for minimum offset voltage and differential thermal re-
sponse, and they can be used for switching and amplifying applications in +0.1V
to +10V (+/- 0.05V to +/- 5V) powered systems where low input bias current, low
input capacitance, and fast switching speed are desired. At V
GS
> 0.00V, the
device exhibits enhancement mode characteristics whereas at V
GS
<0.00V the
device operates in the subthreshold voltage region and exhibits conventional
depletion mode characteristics, with well controlled turn-off and sub-threshold
levels that operate the same as standard enhancement mode MOSFETs.
ALD212900A/ALD212900 features high input impedance (2.5 x 10
10
Ω)
and high
DC current gain (>10
8
). A sample calculation of the DC current gain at a drain
output current of 30mA and input current of 300pA at 25°C is 30mA/300pA =
100,000,000, which translates into a dynamic operating current range of about
eight orders of magnitude. A series of four graphs titled “Forward Transfer Char-
acteristic”, with sub-titles of second “expanded (subthreshold)”, third “further
expanded (subthreshold)” and fourth “Low Voltage” illustrates the unique wide
dynamic operating range of these devices.
Generally it is recommended that the V+ pin be connected to the most positive
voltage and the V- and IC (internally-connected) pins to the most negative volt-
age in the system. All other pins must have voltages within these voltage limits
at all times. Standard ESD protection facilities and handling procedures for static
sensitive devices are highly recommended when using these devices.
ORDERING INFORMATION
(“L” suffix
denotes lead-free (RoHS))
Operating Temperature Range*
0°C to +70°C
8-Pin SOIC
Package
ALD212900ASAL
ALD212900SAL
8-Pin Plastic Dip
Package
ALD212900APAL
ALD212900PAL
FEATURES & BENEFITS
• Zero Threshold™ V
GS(th)
= 0.00 V +/-0.01V
• V
OS
(V
GS(th)
match) to 2mV / 10mV max.
• Sub-threshold voltage ( nano-power) operation
• < 100 mV Min. operating voltage
• < 1 nA Min. operating current
• < 1 nW Min. operating power
• > 100,000,000:1 operating current ranges
• High transconductance and output conductance
• Low R
DS(ON)
of 14Ω
• Output current > 50 mA
• Matched and tracked tempco
• Tight lot-to-lot parametric control
• Positive, zero, and negative V
GS(th)
tempco
• Low input capacitance and leakage currents
APPLICATIONS
• Low overhead current mirrors and current sources
• Zero Power Normally-On circuits
• Energy harvesting circuits
• Very low voltage analog and digital circuits
• Zero power fail-safe circuits
• Backup battery circuits & power failure detector
• Extremely low level voltage-clamps
• Extremely low level zero-crossing detector
• Matched source followers and buffers
• Precision current mirrors and current sources
• Matched capacitive probes and sensor interfaces
• Charge detectors and charge integrators
• High gain differential amplifier input stage
• Matched peak-detectors and level-shifters
• Multiple Channel Sample-and-Hold switches
• Precision Current multipliers
• Discrete matched analog switches / multiplexers
• Nanopower discrete voltage comparators
PIN CONFIGURATION
ALD212900
V-
V-
IC*
G
N1
D
N1
S
12
1
2
3
4
8
7
V+
G
N2
D
N2
V-
M1
M2
6
V-
5
SAL, PAL PACKAGES
*IC pins are internally connected, connect to V-
* Contact factory for industrial temp. range or user-specified threshold voltage values.
©2013 Advanced Linear Devices, Inc., Vers. 1.0
www.aldinc.com
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