Datasheet TCN4040E-2.5EZB, TCN4040E-2.5ENB, TCN4040D-2.5EZB, TCN4040D-2.5ENB, TCN4040D-2.5EOA Datasheet (TelCom Semiconductor)
...
PRECISION MICROPOWER
PRELIMINARY INFORMATION
SHUNT VOLTAGE REFERENCE
PRECISION MICROPOWER SHUNT VOLTAGE REFERENCE
TCN4040
TCN4040
FEATURES
■ Small Packages ....... SOT-23B-3, TO-92, and SO-8
■ Output Capacitor Not Required
■ Handles Capacitive Loads
■ Fixed Reverse Breakdown Voltage of 2.5V
■ Low Output Noise
■ Wide Operating Current Range (60µA to 15mA)
■ – 40°C to + 85°C Operating Temperature Range
GENERAL DESCRIPTION
For applications in tight quarters, the TCN4040 precision voltage reference is available in a space-saving
3mm x 1.3mm SOT-23B-3 surface mount package. The
TCN4040 eliminates the need for an external stabilizing
capacitor while maintaining stability with any capacitive
load. The minimum operating current is 60µA. The maximum operating current is 15mA.
To ensure that the prime parts have an accuracy of
APPLICATIONS
■ Portable, Battery-Powered Equipment
■ Data Acquisition Systems
■ Instrumentation
■ Process Control
■ Energy Management
■ Product Testing
■ Automotive
■ Precision Audio Components
better than ±0.5% (C grade) at 25°C, the TCN4040 uses
fuse and zener-zap reverse breakdown voltage trim during
wafer sort. Low dynamic impedance and bandgap reference
temperature drift curvature correction maintain stable reverse breakdown voltage accuracy over a wide range of
operating temperatures (– 40°C to + 85°C) and currents
from (60µA to 15mA).
The TCN4040 also is available in both adjustable and
1.2V versions.
ORDERING INFORMATION
Output Voltage Tolerance
Part No. Voltage (V) Package Temp. Coefficient Grade
TCN4040C-2.5ENB 2.5 SOT-23B-3* ±0.5%, 100ppm/°C Max (C Grade)
TCN4040C-2.5EOA 2.5 8-Pin SOIC ±0.5%, 100ppm/°C Max (C Grade)
TCN4040C-2.5EZB 2.5 TO-92 ±0.5%, 100ppm/°C Max (C Grade)
TCN4040D-2.5EOA 2.5 8-Pin SOIC ±1.0%, 150ppm/°C Max (D Grade)
TCN4040D-2.5ENB 2.5 SOT-23B-3* ±1.0%, 150ppm/°C Max (D Grade)
TCN4040D-2.5EZB 2.5 TO-92 ±1.0%, 150ppm/°C Max (D Grade)
TCN4040E-2.5ENB 2.5 SOT-23B-3* ±2.0%, 150ppm/°C Max (E Grade)
TCN4040E-2.5EZB 2.5 TO-92 ±2.0%, 150ppm/°C Max (E Grade)
NOTE: *SOT-23B-3 is equivalent to the JEDEC (TO-236)
PIN CONFIGURATION
8-Pin SOIC
NC
1
NC
2
3
NC
–
4
NOTE: *SOT-23B-3 is equivalent to the JEDEC (TO-236)
TCN4040-01 6/16/97
TelCom Semiconductor reserves the right to make changes in the circuitry and specifications to its devices.
+
8
NC
7
NC
6
NC
5
TCN4040EOA
SOT-23B-3*
(TOP VIEW)
NC
1
2
+
1
3
–
TCN4040ENB
NC
+
TO-92-3
123
TCN4040EZB
–
PRELIMINARY INFORMATION
TCN4040
PRECISION MICROPOWER
SHUNT VOLTAGE REFERENCE
ABSOLUTE MAXIMUM RATINGS* (Note 1)
Reverse Current.......................................................20mA
Forward Current .......................................................10mA
Power Dissipation (TA = 25°C) (Note 2)
SOT-23B-3 Package ......................................230mW
ESD Susceptibility
Human Body Model (Note 3) ................................2kV
Machine Model (Note 3) .....................................200V
*Functional operation above the absolute maximum stress rating is not
implied.
TO-92 Package ..............................................440mW
SO-8 Package ................................................470mW
Storage Temperature ...........................– 65°C to + 150°C
Lead Temperature (Soldering, 10 seconds)
EOA ................................................................+260°C
ENB ................................................................+300°C
EZB.................................................................+300°C
NOTES: 1. Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which
the device is functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see
Characteristics.
the device is not operated under the listed test conditions.
2. The maximum power dissipation must be derated at elevated temperatures and is dictated by T
(junction to ambient thermal resistance), and TA (ambient temperature). The maximum allowable power dissipation at any temperature is
PD
= (T
MAX
the typical thermal resistance (θJA), when board mounted, is 185°C/W for the M package, 326°C/W for the SOT-23B-3 package, and 180°
C/W with 0.4” lead length and 170°C/W with 0.125” lead length for the TO-92-3 package.
3. The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin. The machine model is a 200pF capacitor
discharged directly into each pin.
ELECTRICAL CHARACTERISTICS:
The guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when
J
MAX
– TA) /θ
or the number given in Absolute Maximum Ratings, whichever is lower. For the TCN4040, T
JA
Boldface type specifications apply for TA = TJ = T
tions; T
= TJ = 25°C.
A
OPERATING RATINGS (NOTES 1 AND 2)
Temperature Range
(T
≤ TA ≤ T
MIN
Reverse Current
TCN4040-2.5 ...................................... .60µA to 15mA
) .....................– 40°C ≤ TA ≤ +85°C
MAX
(maximum junction temperature), θ
J
MAX
= 125°C, and
J
MAX
MIN
to T
. All other specifica-
MAX
Electrical
JA
TCN4040CEOA TCN4040DEOA TCN4040EENB
TCN4040CENB TCN4040DENB TCN4040EEZB
TCN4040CEZB TCN4040DEZB
Symbol Parameter Test Min Typ Max Min Typ Max Min Typ Max Unit
Conditions
V
R
I
R
MIN
∆VR/∆T Average Reverse IR =10mA — ±20 ±100 — ±20 ±150 — ±20 ±150 ppm/°C
∆V
R
Z
R
Reverse Breakdown
IR =100µA — 2.500 — — 2.500 — — 2.500 — V
Voltage Notes 4, 5
Reverse Breakdown IR =100µA— ±12 — ±25 — — ±50 mV
Voltage Tolerance Notes 4, 5, 6 — ±29 — ±49 — ±74
Minimum Operating Notes 4, 5 — 45 60 — 45 65 — 45 65 µA
Current — 65 — 70 — 70
Breakdown Voltage I
Temperature I
=1mA ±15 ±15 ±15
R
=100µA ±15 ±15 ±15
R
Coefficient Notes 4, 5
/∆IRReverse Breakdown I
≤ IR ≤ 1mA
R
MIN
— 0.4 0.8 — 0.4 1.0 — 0.4 1.0 mV
Voltage Change with Notes 4, 5 — 1.0 — 1.2 — 1.2
Operating Current
Change
1mA ≤ IR =12mA
— 2.3 6.0 — 2.3 8.0 — 2.3 8.0 mV
— 8.0 — 10.0 — 10.0
Reverse Dynamic
Impedance I
IR =1mA, f = 120Hz,
= 0.1 I
AC
R
— 0.3 0.9 — 0.3 1.1 — 0.3 1.1 Ω
Notes 4, 5
TCN4040-01 6/16/97
2
PRECISION MICROPOWER
SHUNT VOLTAGE REFERENCE
PRELIMINARY INFORMATION
TCN4040
ELECTRICAL CHARACTERISTICS (Cont.):
Boldface type specifications apply for TA = TJ = T
specifications; TA = TJ = 25°C.
MIN
to T
MAX
. All other
TCN4040CEOA TCN4040DEOA TCN4040EENB
TCN4040CENB TCN4040DENB TCN4040EEZB
TCN4040CEZB TCN4040DEZB
Symbol Parameter Test Min Typ Max Min Typ Max Min Typ Max Unit
Conditions
e
N
∆V
R
NOTES: 4. Typicals are at TJ = 25°C and represent most likely parametric norm.
Wideband Noise IR =100µA, — 35— —35— —35— µVmsec
10Hz ≤ f ≤ 10kHz
Notes 4, 5
Reverse Breakdown t =1000hrs — 120 — — 120 — — 120 — ppm/°C
Voltage Long Term T = 25°C ±0.1°C
Stability I
5. Limits are 100% production tested at 25°C.
6. The boldface (over-temperature) limit for Reverse Breakdown Voltage Tolerance is defined as the room temperature Reverse Breakdown
Voltage Tolerance ±[(∆VR/∆T)(65°C)(VR)]. ∆VR/∆T is the VR temperature coefficient, 65°C is the temperature range from – 40°C to the
reference point of 25°C, and VR is the reverse breakdown voltage. The total over-temperature tolerance for the different grades is shown
below:
C-grade: ±1.15% = ±0.5% ±100ppm/°C x 65°C
D-grade: ±1.98% = ±1.0% ±150ppm/°C x 65°C
E-grade: ±2.98% = ±2.0% ±150ppm/°C x 65°C
=100µA
R
Notes 4, 5
PIN DESCRIPTION
Pin No. Pin No. Pin No.
(SOT-23B-3) TO-92 8-Pin SOIC Symbol Description
1 1 1 NC No connection
2 NC No connection
3 NC No connection
2 2 + Positive terminal
3 3 – Negative terminal
4 – Negative terminal
5 NC No connection
6 NC No connection
7 NC No connection
8 + Positive terminal
TCN4040-01 6/16/97
3
PRELIMINARY INFORMATION
TCN4040
PRECISION MICROPOWER
SHUNT VOLTAGE REFERENCE
APPLICATIONS INFORMATION
Available in a space saving SOT-23B-3 surface mount
package, the TCN4040 is a precision micro-power curvature-corrected bandgap shunt voltage reference. The
TCN4040 is designed for stable operation without an external capacitor connected between the “+” pin and the “–” pin.
The TCN4040 also remains stable, however, if a bypass
capacitor is used. The minimum operating current increase
is 60mA and the maximum operating current is 15mA.
The TCN4040, in the SOT-23B-3 package has a parasitic Schottky diode between pin 3 (–) and pin 1. (Die attach
interface contact). Therefore, pin 1 of the SOT-23B-3 package must be left floating or connected to pin 3.
In a conventional shunt regulator application, an external series resistor (RS) is connected between the supply
voltage and the TCN4040 (Figure 1). RS determines the
current that flows through the load (IL) and the TCN4040
(IQ). Even when the supply voltage is at its minimum, and
the load current is at its maximum value, RS should be small
enough to supply at least the minimum acceptable IQ to the
TCN4040 since load current and supply voltage may vary.
Conversely, when the supply voltage is at its maximum and
IL is at its minimum, RS should be large enough that the
current flowing through the TCN4040 is less than 15mA.
RS is determined by the supply voltage, (VS), the load
and operating current, (IL and IQ), and the TCN4040’s
reverse breakdown voltage, VR.
VS – V
R
RS =
IL + I
Q
V
S
R
S
V
R
TCN4040
Figure 1. Shunt Regulator
IQ + I
I
I
Q
L
L
TCN4040-01 6/16/97
4
PRECISION MICROPOWER
PRELIMINARY INFORMATION
SHUNT VOLTAGE REFERENCE
PRECISION MICROPOWER SHUNT VOLTAGE REFERENCE
TCN4041
TCN4041
FEATURES
■ Small Packages ....... SOT-23B-3, TO-92, and SO-8
■ Output Capacitor Not Required
■ Handles Capacitive Loads
■ Adjutable Voltage and Fixed Reverse Breakdown
Voltage of 1.2V
■ Low Output Noise
■ Wide Operating Current Range (60µA to 15mA)
■ – 40°C to + 85°C Operating Temperature Range
APPLICATIONS
■ Portable, Battery-Powered Equipment
■ Data Acquisition Systems
■ Instrumentation
■ Process Control
■ Energy Management
■ Product Testing
■ Automotive
■ Precision Audio Components
GENERAL DESCRIPTION
For applications in tight quarters, the TCN4041 precision voltage reference is available in a space-saving
3mm x 1.3mm SOT-23B-3 surface mount package. The
TCN4041 eliminates the need for an external stabilizing
capacitor while maintaining stability with any capacitive
load. The minimum operating current is for both the TCN4041-
1.2V and the TCN4041-ADJ. Both versions have a maximum operating current of 12mA.
To ensure that the prime parts have an accuracy of
better than ±0.5% (C grade) at 25°C, the TCN4041 uses
fuse and zener-zap reverse breakdown voltage trim during
wafer sort. Low dynamic impedance and bandgap reference
temperature drift curvature correction maintain stable reverse breakdown voltage accuracy over a wide range of
operating temperatures (– 40°C to + 85°C) and currents
from (60µA to 12mA).
The TCN4041 is available in small SOT-23, TO-92, and
SO-8 packages.
ORDERING INFORMATION
Output Voltage Tolerance
Part No. Voltage (V) Package Temp. Coefficient Grade
TCN4041C-1.2ENB 1.2 SOT-23B-3* ±0.5%, 100ppm/°C Max (C Grade)
TCN4041C-ADJENB ADJ SOT-23B-3* ±0.5%, 100ppm/°C Max (C Grade)
TCN4041C-1.2EOA 1.2 8-Pin SOIC ±0.5%, 100ppm/°C Max (C Grade)
TCN4041C-ADJEOA ADJ 8-Pin SOIC ±0.5%, 100ppm/°C Max (C Grade)
TCN4041C-1.2EZB 1.2 TO-92 ±0.5%, 100ppm/°C Max (C Grade)
TCN4041C-ADJEZB ADJ TO-92 ±0.5%, 100ppm/°C Max (C Grade)
TCN4041D-2.5EOA 2.5 8-Pin SOIC ±1.0%, 150ppm/°C Max (D Grade)
TCN4041D-4.1EOA 4.1 8-Pin SOIC ±1.0%, 150ppm/°C Max (D Grade)
TCN4041D-1.2ENB 1.2 SOT-23B-3* ±1.0%, 150ppm/°C Max (D Grade)
TCN4041D-ADJENB ADJ SOT-23B-3* ±1.0%, 150ppm/°C Max (D Grade)
TCN4041D-1.2EZB 1.2 TO-92 ±1.0%, 150ppm/°C Max (D Grade
TCN4041D-ADJEZB ADJ TO-92 ±1.0%, 150ppm/°C Max (D Grade)
TCN4041E-1.2ENB 1.2 SOT-23B-3* ±2.0%, 150ppm/°C Max (E Grade)
TCN4041E-1.2EZB 1.2 TO-92 ±2.0%, 150ppm/°C Max (E Grade)
NOTE: *SOT-23B-3 is equivalent to the JEDEC (TO-236)
TCN4041-01 6/19/97
TelCom Semiconductor reserves the right to make changes in the circuitry and specifications to its devices.
1
PRELIMINARY INFORMATION
TCN4041
PRECISION MICROPOWER
SHUNT VOLTAGE REFERENCE
ABSOLUTE MAXIMUM RATINGS* (Note 1)
Reverse Current.......................................................20mA
Forward Current .......................................................10mA
Power Dissipation (TA = 25°C) (Note 2)
SOT-23B-3 Package ......................................230mW
TO-92 Package ..............................................440mW
SO-8 Package ................................................470mW
Storage Temperature ...........................– 65°C to + 150°C
Lead Temperature (Soldering, 10 seconds)
EOA ................................................................+260°C
ENB ................................................................+300°C
EZB.................................................................+300°C
ESD Susceptibility
NOTES: 1. Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which
ELECTRICAL CHARACTERISTICS:
the device is functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see
Characteristics.
the device is not operated under the listed test conditions.
2. The maximum power dissipation must be derated at elevated temperatures and is dictated by T
(junction to ambient thermal resistance), and TA (ambient temperature). The maximum allowable power dissipation at any temperature is
PD
= (T
MAX
the typical thermal resistance (θJA), when board mounted, is 185°C/W for the M package, 326°C/W for the SOT-23B-3 package, and 180°
C/W with 0.4” lead length and 170°C/W with 0.125” lead length for the TO-92-3 package.
3. The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin. The machine model is a 200pF capacitor
discharged directly into each pin.
The guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when
J
MAX
– TA) /θ
or the number given in Absolute Maximum Ratings, whichever is lower. For the TCN4041, T
JA
Boldface type specifications apply for TA = TJ = T
Human Body Model (Note 3) ................................2kV
Machine Model (Note 3) .....................................200V
*Functional operation above the absolute maximum stress rating is not
implied.
OPERATING RATINGS (NOTES 1 AND 2)
Temperature Range
(T
≤ TA ≤ T
MIN
Reverse Current
TCN4041-1.2 ....................................... 60µA to 12mA
TCN40401-ADJ ....................................68µA to12mA
Output Voltage Range
TCN4041-ADJ ....................................... 1.24V to 10V
) .....................– 40°C ≤ TA ≤ +85°C
MAX
(maximum junction temperature), θ
J
MAX
= 125°C, and
J
MAX
MIN
to T
. All other specifica-
MAX
Electrical
tions; TA = TJ = 25°C. All other specifications; TA = TJ = 25°C. The grades C, D,
and E designate initial Reverse Breakdown Voltage tolerances of ±0.5%, ±1.0%,
and ±2.0%, respectively.
JA
TCN4041CEOA TCN4041DEOA TCN4041EENB
TCN4041CENB TCN4041DENB TCN4041EEZB
TCN4041CEZB TCN4041DEZB
Symbol Parameter Test Min Typ Max Min Typ Max Min Typ Max Unit
Conditions
V
R
I
R
MIN
∆V
R
∆VR/∆IRReverse Breakdown I
Z
R
TCN4041-01 6/19/97
Reverse Breakdown
IR =100µA — 1.225 — — 2.500 — — 2.500 — V
Voltage Notes 4, 5
Reverse Breakdown IR =100µA— ±6— ±12 — — ±25 mV
Voltage Tolerance Notes 4, 5, 6 — ±14 — ±24 — ±36
Minimum Operating Notes 4, 5 — 45 60 — 45 65 — 45 65 µA
Current — 65 — 70 — 70
/∆T Average Reverse IR =10mA — ±20 ±100 — ±20 ±160 — ±20 ±150 ppm/°C
Breakdown Voltage I
Temperature I
=1mA ±15 ±15 ±15
R
=100µA ±15 ±15 ±15
R
Coefficient Notes 4, 5
≤ IR ≤ 1mA
R
MIN
— 0.7 1.5 — 0.4 2.0 — 0.4 2.0 mV
Voltage Change with Notes 4, 5 — 2.0 — 2.5 — 2.5
Operating Current
Change
1mA ≤ IR =12mA
— 2.5 6.0 — 2.3 8.0 — 2.3 8.0 mV
— 8.0 — 10.0 — 10.0
Reverse Dynamic
Impedance I
IR =1mA, f = 120Hz,
= 0.1 I
AC
R
— 0.5 1.5 — 0.3 2.0 — 0.3 2.0 Ω
Notes 4, 5
2
PRECISION MICROPOWER
SHUNT VOLTAGE REFERENCE
PRELIMINARY INFORMATION
TCN4041
ELECTRICAL CHARACTERISTICS (Cont.):
Boldface type specifications apply for TA = TJ = T
MIN
to T
MAX
. All other
specifications; TA = TJ = 25°C. The grades C, D, and E designate initial
Reverse Breakdown Voltage tolerances of ±0.5%, ±1.0%, and ±2.0%,
respectively.
TCN4041CEOA TCN4041DEOA TCN4041EENB
TCN4041CENB TCN4041DENB TCN4041EEZB
TCN4041CEZB TCN4041DEZB
Symbol Parameter Test Min Typ Max Min Typ Max Min Typ Max Unit
Conditions
e
N
∆V
R
NOTES: 4. Typicals are at TJ = 25°C and represent most likely parametric norm.
Wideband Noise IR =100µA, — 20— —20— —20— µVmsec
10Hz ≤ f ≤ 10kHz
Notes 4, 5
Reverse Breakdown t =1000hrs — 120 — — 120 — — 120 — ppm/°C
Voltage Long Term T = 25°C ±0.1°C
Stability I
=100µA
R
Notes 4, 5
5. Limits are 100% production tested at 25°C.
6. The boldface (over-temperature) limit for Reverse Breakdown Voltage Tolerance is defined as the room temperature Reverse Breakdown
Voltage Tolerance ±[(∆VR/∆T)(65°C)(VR)]. ∆VR/∆T is the VR temperature coefficient, 65°C is the temperature range from – 40°C to the
reference point of 25°C, and VR is the reverse breakdown voltage. The total over-temperature tolerance for the different grades is shown
below:
C-grade: ±1.15% = ±0.5% ±100ppm/°C x 65°C
D-grade: ±1.98% = ±1.0% ±150ppm/°C x 65°C
E-grade: ±2.98% = ±2.0% ±150ppm/°C x 65°C
7. When VOUT ≤ 1.6V, the TCN4041-ADJ in the SOT-23B package must operate at reduced IR. This is caused by the series resistance of the
die attach between the die (-) output and the package (-) output pin. See the Output Saturation (SOT23-B only) curve in the
Characteristics
8. Reference voltage and temperature coefficient will change with output voltage. See
section.
Typical Characteristics
curves.
Typical
PIN CONFIGURATION
TO-92-3
123
TCN4041EZB-1.2V
123
+
–
NC
TCN4041-ADJ
NOTE: *SOT-23B-3 is equivalent to the JEDEC (TO-236)
SOT-23B-3*
(TOP VIEW)
NC
1
2
+
TCN4041ENB-1.2V
2
+
TCN4041ENB-ADJ
3
–
NC
1
3
–
8-Pin SOIC
NC
1
NC
2
3
NC
–
4
TCN4041EOA-1.2V
NC
1
NC
2
3
NC
–
4
TCN4041EOA-ADJ
8
7
6
5
8
7
6
5
+
NC
NC
NC
+
NC
NC
NC
TCN4041-01 6/19/97
3
PRELIMINARY INFORMATION
PRECISION MICROPOWER
SHUNT VOLTAGE REFERENCE
TCN4041
PIN DESCRIPTION
Pin No. Pin No. Pin No.
(SOT-23B-3) TO-92 8-Pin SOIC Symbol Description
1 1 1 NC No connection
2 NC No connection
3 NC No connection
2 2 + Positive terminal
3 3 – Negative terminal
4 – Negative terminal
5 NC No connection
6 NC No connection
7 NC No connection
8 + Positive terminal
APPLICATIONS INFORMATION
Available in space-saving SOT-23B-3 surface
mount packages, the TCN4041 is a precision micro-power
curvature-corrected bandgap shunt voltage reference. It is
designed for stable operation without an external capacitor
connected between the “+” pin and the “-” pin. The TCN4041
also remains stable, however, if a bypass capacitor is used.
The device is available in either a fixed 1.2V or an adjustable
reverse breakdown voltage. The minimum operating current is 60mA, and the maximum operating current is 12mA
for both options.
TCN4041s in the SOT-23 package have pin 1
connected as the (-) output. (Die attach interface contact).
Therefore, pin 1 of the TCN4041-1.2 must be left floating or
connected to pin 3, and pin 1 on the TCN4041-ADJ is the
(-) output.
In a conventional shunt regulator application, an
external series resistor (RS) is connected between the
supply voltage and the TCN4041 (Figure 1). RS determines
the current that flows through the load (IL) and the TCN4041
(IQ). Even when the supply voltage is at its minimum, and
the load current is at its maximum value, RS should be small
enough to supply at least the minimum acceptable IQ to the
TCN4041 since load current and supply voltage may vary.
Conversely, when the supply voltage is at its maximum and
IL is at its minimum, RS should be large enough that the
current flowing through the TCN4041 is less than 12mA.
RS is determined by the supply voltage, (VS), the
load and operating current, (IL and IQ), and the TCN4041’s
reverse breakdown voltage, VR.
VS - V
R
RS =
IL + I
Q
Output voltage on the TCN4041-ADJ can be adjusted to
any value between 1.24V and 10V. It is a function of the
internal reference voltage (V
) and the ratio of the external
REF
feedback resistors (see Figure 2). The output can be found
with the equation (where V
V
= V
OUT
The value of the internal V
“corrected” V
can be determined by (where VO is the
REF
is the desired output voltage):
OUT
(R2/R1 + 1)
REF
Equation 1.
is a function of VO. The
REF
desired output voltage):
V
= V
REF’
∆V
REF
/∆V
is typically -1.3mV/V, and VY = 1.240V.
OUT
Replace the value of V
OUT ∆VREF
Equation 2.
in Equation 1 with the value
REF’
/∆V
OUT
) +V
Y
determined using Equation 2.
The actual output voltage can deviate from that predicted by the typical ∆V
case ∆V
REF
/∆V
for C-grade parts is – 2.5mV/V and
OUT
/∆VO in Equation 2. The worst
REF
VY = 1.246V; for D-grade, the worst case is – 3.0mV/V and
VY = 1.248V.
The difference in output voltage resulting from typical
worst case values are shown in the following example: Let
VO = +9V. Using the typical value of ∆V
REF
/∆V
OUT
, V
REF
is
1.228; choosing a value of R1 = 10kΩ, R2 = 63.272kW. The
output voltage, when using worst case ∆V
REF
/∆V
OUT
for
C-grade and D-grade parts, is 8.965V and 8.946V, respectively. This could result in errors as large as 0.39% for
C-grade, and 0.59% for D-grade parts. However, resistor
values resulting from the typical value of ∆V
REF
/∆V
OUT
will
work most of the time, requiring no additional adjustments.
TCN4041-01 6/19/97
4
PRECISION MICROPOWER
R
S
R
1
R
2
V
OUT
V
S
TCN4041-ADJ
SHUNT VOLTAGE REFERENCE
V
S
PRELIMINARY INFORMATION
TCN4041
R
S
V
R
I
I
Q
+
L
I
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TCN4041
Figure 1. Shunt Regulator
Figure 2. Adjustable Shunt
TCN4041-01 6/19/97
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