MOSFET ARRAY. ALD114904 Datasheet

ALD114904 ARRAY. Datasheet pdf. Equivalent

Part ALD114904
Description PRECISION MATCHED PAIR MOSFET ARRAY
Feature ADVANCED LINEAR DEVICES, INC. PERFORMANCE CHARACTERISTICS OF EPAD® PRECISION MATCHED PAIR MOSFET ARR.
Manufacture Advanced Linear Devices
Datasheet
Download ALD114904 Datasheet



ALD114904
ADVANCED
LINEAR
DEVICES, INC.
PERFORMANCE CHARACTERISTICS OF EPAD®
PRECISION MATCHED PAIR MOSFET ARRAY
e TM
EPAD ®
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GENERAL DESCRIPTION
ALD1108xx/ALD1109xx/ALD1148xx/ALD1149xx are high precision
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.
ALD’s Electrically Programmable Analog Device (EPAD) technol-
ogy provides a family of matched transistors with a range of preci-
sion threshold values. All members of this family are designed and
actively programmed for exceptional matching of device electrical
characteristics. Threshold values range from -3.50V Depletion to
+3.50V Enhancement devices, including standard products speci-
fied at -3.50V, -1.30V, -0.40V, +0.00V, +0.20V, +0.40V, +0.80V,
+1.40V, and +3.30V. ALD can also provide any customer desired
value between -3.50V and +3.50V. For all these devices, even the
depletion and zero threshold transistors, ALD EPAD technology
enables the same well controlled turn-off, subthreshold, and low
leakage characteristics as standard enhancement mode MOSFETs.
With the design and active programming, even units from different
batches and different dates of manufacture have well matched char-
acteristics. As these devices are on the same monolithic chip, they
also exhibit excellent tempco tracking.
This EPAD MOSFET Array product family (EPAD MOSFET) is avail-
able in the three separate categories, each providing a distinctly
different set of 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 cat-
egory is the ALD1148xx/ALD1149xx depletion mode EPAD
MOSFETs. (The suffix “xx” denotes threshold voltage in 0.1V steps,
for example, xx = 08 denotes 0.80V).
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 = 1µA @ VDS = 0.1V
when the gate voltage VGS = 0.00V. Zero threshold devices oper-
ate in the enhancement region when operated above threshold volt-
age and current level (VGS > 0.00V and IDS > 1µA) and subthresh-
old region when operated at or below threshold voltage and current
level (VGS <= 0.00V and IDS < 1µA). This device, along with other
very low threshold voltage members of the product family, consti-
tute a class of EPAD MOSFETs that enable ultra low supply volt-
age operation and nanopower type of circuit designs, applicable in
either analog or digital circuits.
The ALD1108xx/ALD1109xx (quad/dual) product family features pre-
cision matched enhancement mode EPAD MOSFET devices, which
require a positive bias voltage to turn on. Precision threshold val-
ues 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 20nA.
The ALD1148xx/ALD1149xx (quad/dual) features depletion mode
EPAD MOSFETs, which are normally-on devices when the gate
bias voltage is at zero volts. 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 VGS = 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, modu-
lated 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 ideal for minimum offset voltage and differen-
tial thermal response, and they are used for switching and amplify-
ing applications in low voltage (1V to 10V or +/-0.5V to +/-5V) or
ultra low voltage (less than 1V or +/-0.5V) systems. They feature
low input bias current (less than 30pA max.), ultra low power
(microWatt) or Nanopower (power measured in nanoWatt) opera-
tion, low input capacitance and fast switching speed. These de-
vices can be used where a combination of these characteristics
are desired.
KEY APPLICATION ENVIRONMENT
EPAD MOSFET Array products are for circuit applications in one or
more of the following operating environments:
* Low voltage: 1V to 10V or +/-0.5V to +/-5V
* Ultra low voltage: less than 1V or +/-0.5V
* Low power: voltage x current = power measured in microwatt
* Nanopower: voltage x current = power measured in nanowatt
* Precision matching and tracking of two or more MOSFETs
PIN CONFIGURATIONS
QUAD
V-
IC* 1
V-
16
GN1
DN1
S12
V-
2
3
4
5
M1
V-
M2
V+
15
14
13
12
DN4 6
M4 M3
11
GN4 7
10
IC* 8 V-
V- 9
IC*
GN2
DN2
V+
S34
DN3
GN3
IC*
IC*
GN1
DN1
S12
SCL, PCL PACKAGES
DUAL
V-
1
V-
8
2
3 M1 M2
7
6
4 V- 5
IC*
GN2
DN2
V-
SAL, PAL PACKAGES
*IC pins are internally connected, connect to V-
©2016 Advanced Linear Devices, Inc., Vers. 2.3
www.aldinc.com
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ALD114904
PERFORMANCE CHARACTERISTICS OF EPAD®
PRECISION MATCHED PAIR MOSFET FAMILY
ELECTRICAL CHARACTERISTICS
The turn-on and turn-off electrical characteristics of the EPAD
OSFET products are shown in the Drain-Source On Current vs
Drain-Source On Voltage and Drain-Source On Current vs Gate-
Source Voltage graphs. Each graph show the Drain-Source On
Current versus Drain-Source On Voltage characteristics as a func-
tion of Gate-Source voltage in a different operating region under
different bias conditions. As the threshold voltage is tightly speci-
fied, the Drain-Source On Current at a given gate input voltage is
better controlled and more predictable when compared to many
other types of MOSFETs.
EPAD MOSFETs behave similarly to a standard MOSFET, there-
fore classic equations for a n-channel MOSFET applies to EPAD
MOSFET as well. The Drain current in the linear region (VDS <
VGS - VGS(th)) is given by:
IDS = u . COX . W/L . [VGS - VGS(th) - VDS/2] . VDS
where:
u = Mobility
COX = Capacitance / unit area of Gate electrode
VGS = Gate to Source voltage
VGS(th) = Turn-on threshold voltage
VDS = Drain to Source voltage
W = Channel width
L = Channel length
In this region of operation the IDS value is proportional to VDS value
and the device can be used as a gate-voltage controlled resistor.
LOW POWER AND NANOPOWER
When supply voltages decrease, the power consumption of a given
load resistor decreases as the square of the supply voltage. So
one of the benefits in reducing supply voltage is to reduce power
consumption. While decreasing power supply voltages and power
consumption go hand-in-hand with decreasing useful AC bandwidth
and at the same time increases noise effects in the circuit, a circuit
designer can make the necessary tradeoffs and adjustments in
any given circuit design and bias the circuit accordingly.
With EPAD MOSFETs, a circuit that performs a specific function
can be designed so that power consumption can be minimized. In
some cases, these circuits operate in low power mode where the
power consumed is measure in micro-watts. In other cases, power
dissipation can be reduced to the nano-watt region and still pro-
vide a useful and controlled circuit function operation.
ZERO TEMPERATURE COEFFICIENT (ZTC) OPERATION
For an EPAD MOSFET in this product family, there exist operating
points where the various factors that cause the current to increase
as a function of temperature balance out those that cause the cur-
rent to decrease, thereby canceling each other, and resulting in net
temperature coefficient of near zero. One of this temperature stable
operating point is obtained by a ZTC voltage bias condition, which
is 0.55V above a threshold voltage when VGS = VDS, resulting in a
temperature stable current level of about 68µA. For other ZTC op-
erating points, see ZTC characteristics.
For higher values of VDS where VDS >= VGS - VGS(th), the satura-
tion current IDS is now given by (approx.):
IDS = u . COX . W/L . [VGS - VGS(th)]2
SUB-THRESHOLD REGION OF OPERATION
Low voltage systems, namely those operating at 5V, 3.3V or less,
typically require MOSFETs that have threshold voltage of 1V or
less. The threshold, or turn-on, voltage of the MOSFET is a voltage
below which the MOSFET conduction channel rapidly turns off. For
analog designs, this threshold voltage directly affects the operating
signal voltage range and the operating bias current levels.
At or below threshold voltage, an EPAD MOSFET exhibits a turn-
off characteristic in an operating region called the subthreshold re-
gion. This is when the EPAD MOSFET conduction channel rapidly
turns off as a function of decreasing applied gate voltage. The con-
duction channel induced by the gate voltage on the gate electrode
decreases exponentially and causes the drain current to decrease
exponentially. However, the conduction channel does not shut off
abruptly with decreasing gate voltage. Rather, it decreases at a
fixed rate of approximately 116mV per decade of drain current de-
crease. Thus, if the threshold voltage is +0.20V, for example, the
drain current is 1µA at VGS = +0.20V. At VGS = +0.09V, the drain
current would decrease to 0.1µA. Extrapolating from this, the drain
current is 0.01µA (10nA) at VGS = -0.03V, 1nA at VGS = -0.14V,
and so forth. This subthreshold characteristic extends all the way
down to current levels below 1nA and is limited by other currents
such as junction leakage currents.
At a drain current to be declared “zero current” by the user, the
VGS voltage at that zero current can now be estimated. Note that
using the above example, with VGS(th) = +0.20V, the drain current
still hovers around 20nA when the gate is at zero volts, or ground.
PERFORMANCE CHARACTERISTICS
Performance characteristics of the EPAD MOSFET product family
are shown in the following graphs. In general, the threshold volt-
age shift for each member of the product family causes other af-
fected electrical characteristics to shift with an equivalent linear
shift in VGS(th) bias voltage. This linear shift in VGS causes the
subthreshold I-V curves to shift linearly as well. Accordingly, the
subthreshold operating current can be determined by calculating
the gate voltage drop relative from its threshold voltage, VGS(th).
RDS(ON) AT VGS = GROUND
Several of the EPAD MOSFETs produce a fixed resistance when
their gate is grounded. For ALD110800, the drain current is 1µA at
VDS = 0.1V and VGS = 0.0V. Thus, just by grounding the gate of
the ALD110800, a resistor with RDS(ON) = ~100Kis produced.
When an ALD114804 gate is grounded, the drain current IDS =
18.5µA @ VDS = 0.1V, producing RDS(ON) = 5.4K. Similarly,
ALD114813 and ALD114835 produce drain currents of 77µA and
185µA, respectively, at VGS = 0.0V, and RDS(ON) values of 1.3K
and 540, respectively.
MATCHING CHARACTERISTICS
A key benefit of using matched-pair EPAD MOSFET is to maintain
temperature tracking. In general, for EPAD MOSFET matched pair
devices, one device of the matched pair has gate leakage cur-
rents, junction temperature effects, and drain current temperature
coefficient as a function of bias voltage that cancel out similar ef-
fects of the other device, resulting in a temperature stable circuit.
As mentioned earlier, this temperature stability can be further en-
hanced by biasing the matched-pairs at Zero Tempco (ZTC) point,
even though that could require special circuit configuration and
power consumption design consideration.
ALD1108xx/ALD1109xx/ALD1148xx/ALD1149xx
PERFORMANCE CHARACTERISTICS, Vers. 2.3
Advanced Linear Devices
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