VHP4Z, VPR247Z
Bulk Metal® Z- Foil Technology Ultra High Precision
Hermetically Sealed 4-Terminal Power Current Sensing Resistors with
TCR as Low as 0.05 ppm/°C and Power up to 10 Watts
FEATURES
Temperature coefficient of resistance TCR:
0.05 ppm/°C typical (0 °C to + 60 °C)
+0.2 ppm/°C typical (- 55 °C to + 125 °C,
+ 25 °C ref.)
Resistance range: 0.25to 500
Tolerance: to ± 0.01 % (see table 1)
Power rating (heat-sinked): 10 W (see table 2)
INTRODUCTION
Vishay Foil Resistors (VFR) Model VHP-4Z offers welded
construction and screw mounting directly to a metal heat sink
for maximum heat transfer. Hermetic sealing and nitrogen
back fill provide the maximum protection against
environmental stresses, thereby ensuring long term stability.
A special feature of this construction is Kovar eyelet’s and
solder-plated OFHC copper leads providing the lowest
thermal EMFs in the industry.
VFR Model VPR247Z has many of the advantages of the
VHP4Z but with significantly reduced size and weight. It also
has gold plated copper leads.
These series should be selected where rapid R stabilization
and resistance stability under transient power conditions is
required. These products achieve optimum performance
when mounted on a chassis or cooled heat sink. The Z-Foil
technology provides extremely low PCR under defined
conditions (see figure 2 and figure 3). The low absolute TCR
provided by the Z-Foil technology is measured over the
temperature range of - 55 °C to + 125 °C or 0 °C to + 60 °C,
+ 25 °C reference (see figure 7).
All of these devices utilizing the Z-Foil technology are
provided with a true 4 terminal Kelvin connection. This is a
must for precise current sensing when the resistance value
is less than 100 (see figure 4).
Load life stability:
± 0.005 % typical (50 ppm), 3 W on heatsink at + 25 °C,
2000 h
± 0.01 % typical (100 ppm), 3 W in free air at + 25 °C,
2000 h
± 0.01 % typical (100 ppm), 10 W on heatsink at + 25 °C,
2000 h
Vishay Foil resistors are not restricted to standard values,
we can supply specific “as required” values at no extra cost
or delivery (e.g. 1K2345 vs. 1K)
Thermal stabilization time < 1 s (nominal value achieved
within 10 ppm of steady state value)
Electrostatic discharge (ESD) at least to 25 kV
Non inductive, non capacitive design
Rise time: 1 ns effectively no ringing
Current noise: 0.010 µVRMS/V of applied voltage (< - 40 dB)
Voltage coefficient < 0.1 ppm/V
Non inductive: < 0.08 µH
Non hot spot design
Terminal finishes available:
VHP-4Z:
lead (Pb)-free or tin/lead alloy
VPR247Z:
gold plated
Custom high power designs can be developed for your
specific applications, for more information please contact us.
FIGURE 1 - POWER DERATING CURVE
RATED POWER (%)
- 55 °C
TABLE 1 - TOLERANCE AND TCR VS.
RESISTANCE VALUE (- 55 °C to + 125 °C,
+ 25 °C Ref.)
RESISTANCE
RANGE ()
TIGHTEST
TOLERANCE
10 to < 500
± 0.01 %
5 to < 10
± 0.02 %
2 to < 5
± 0.05 %
1 to < 2
± 0.1 %
0.5 to < 1
± 0.25 %
0.25 to < 0.5
±0.5 %
+ 25 °C
100
75
50
25
0
- 50
0
+ 50
+ 100
+ 150
+ 200
AMBIENT TEMPERATURE
TYPICAL TCR
AND MAX.
SPREAD
(ppm/°C)
± 0.2 ± 1.8
± 0.2 ± 2.8
* Pb containing terminations are not RoHS compliant, exemptions may apply
Document Number: 63239
Revision: 10-Mar-15
For any questions, contact
foil@vpgsensors.com
www.vishayfoilresistors.com
1
VHP4Z, VPR247Z
TABLE 2 - GENERAL SPECIFICATIONS(4)
4 ppm/Watt Maximum
(Mounted on a cooled heat sink held at + 25 °C)
Power Coefficient of Resistance (PCR)
Power Rating
At + 25 °C (see Fig. 1)
10 W or 3 A (whichever is lower) - heat sink(1)
3 W or 3 A (whichever is lower) - free air
Current Noise
< 0.010 µV (RMS)/V of applied voltage
(- 40 dB)
High Frequency Operation
Rise time
1.0 ns at 1 k without ringing
Inductance (L)(2)
0.1 µH maximum; 0.08 µH typical
Capacitance (C)
1.0 pF maximum; 0.5 pF typical
Thermal resistance
6 °C/W
Operating Temperature Range
- 55 °C to + 150 °C
Hermeticity
10-7 Atmospheric cc/s maximum
Maximum Working Voltage(3)
600 V
Thermal EMF
0.1 µV/°C maximum (lead effect)
2.5 µV/W maximum (power effect)
Notes
1. Heat sink chassis
MIL-PRF-39009/1:
dimensions
and
requirements
per
2. Inductance (L) due mainly to the leads.
3. Maximum ambient temperature is + 150 °C.
INCHES
MM
L
6.00
152.4
W
4.00
101.6
H
2.00
50.8
T
0.04
1.0
4. Weight: VHP4Z = 15 g maximum , VPR247Z = 7 g maximum.
TABLE 3 - ENVIRONMENTAL PERFORMANCE
(1)
TYPICAL R LIMITS
MAXIMUM R LIMITS
Thermal Shock
0.01 %
0.02 %
Short Time Overload (5 x rated power for 5 s)
0.01 %
0.02 %
TEST OR CONDITION
Terminal Strength
0.02 %
0.05 %
High Temperature Exposure (2000 h at + 150 °C)
0.02 %
0.05 %
Moisture Resistance
0.02 %
0.05 %
Low Temperature Storage (24 h at - 55 °C)
0.005 %
0.01 %
Shock (specified pulse)
0.01 %
0.02 %
Vibration (high frequency)
0.01 %
0.02 %
Load Life (rated power(3), + 25 °C, 2000 h)
0.01 %
0.02 %
Note
(1) R’s plus additional 0.0005 for measurement error
(2) Maximum overload rating is 15 W (5 x rated power in free air; 1.5 x rated power on heatsink), with applied voltage not to exceed 750 V.
(3) 3W in free air or 10W on heat sink
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Document Number: 63239
Revision: 10-Mar-15
VHP4Z, VPR247Z
FIGURE 3 - POWER COEFFICIENT (PCR)
RESISTANCE DEVIATION, ppm
RESISTANCE DEVIATION, ppm
FIGURE 2 - RAPID STABILIZATION
15
10
5
0
-5
- 10
- 15
0
20
40
60
80
100
120
140
60
40
20
0
- 20
- 40
- 60
0
5
8
APPLIED POWER, W
RESISTANCE CHANGE VS APPLIED POWER
MOUNTED ON COOLED HEAT SINK HELD AT + 25 °C
160 180 200
TIME, s
RESISTANCE CHANGE UNDER LOAD AT 10 WATTS
MOUNTED ON COOLED HEAT SINK HELD AT + 25 °C
1
2
10
FIGURE 4 - KELVIN CONNECTION
r1
I1
R
r3
Im
Kelvin (4-terminal) connections are used for these low ohmic value products to
r2
I2 measure a precise voltage drop across the resistive element. In these
applications the contact resistance, lead resistance, and their TCR effect may
be greater than that of the element itself and could cause significant errors if
the standard 2-terminal connection is used. Figure 4 shows a high impedance
measurement system where r5 approaches infinity and Im approaches zero
resulting in negligible IR drop through r3 and r4 which negates their lead
resistance and TCR effect. With the voltage sense leads E1 and E2 inside of r1
and r2 the resistance and TCR effect of the current leads, I1 and I2 are negated
and only the resistance and TCR of the element R are sensed. This method of
measurement is essential for precise current sensing.
r4
0
r5
∞
0.770 (19.56)
Max. Dia.
0.222
(5.64)
E1
I2
E2
0.156 Dia. (3.9)
± 0.005 (± 0.13)
TO-3 Cap
TO-3 Base
Standard Marking
Arrangement
Print Spec
Model Number
VFR
VHP4Z
12R500
0.1 %
BXXXX
0.45 (11.43)
Min.
I1
0.665 (16.89)
± 0.005 (± 0.13)
1.186 (30.13)
± 0.005 (± 0.13)
1.530 (38.86)
± 0.005 (± 0.13)
Mounting
Hole
0.266 (6.76)
± 0.005 (± 0.13)
0.335 (8.51)
± 0.005 (± 0.13)
FIGURE 5 - VHP4Z STANDARD IMPRINTING AND DIMENSIONS in inches (millimeters)
0.040 (1.00) Dia.
± 0.005 (± 0.13)
0.43 (10.92)
± 0.01 (± 0.25)
1.00 (25.4)
± 0.005 (± 0.13)
Resistance
Value
Tolerance
Date Code
29
B1329 = 13
(Year)(Week)
I1
I2
E1
E2
Case not active; insulators not required; mounting hardware not supplied.
Document Number: 63239
Revision: 10-Mar-15
For any questions, contact
foil@vpgsensors.com
www.vishayfoilresistors.com
3
VHP4Z, VPR247Z
FIGURE 6 - VPR247Z STANDARD IMPRINTING AND DIMENSIONS
B
W
L
0.140 ± 0.005
C
(Dia. Thru Hole)
VFR
VPR247Z
BXXXX
0R2000 1%
H
0.010 Max.
Sleeve Extension
Date Code
10
B1310 = 13
(Year) (Week)
Tolerance
Resistance
Value
I1 E1 E2 I2
S
Gold Plated
Copper Leads
0.025 Dia.
LL
A
LS
INCHES
MM
L
0.690 ± 0.005
17.53 ± 0.13
H
0.820 ± 0.005
20.83 ± 0.13
W
0.215 ± 0.005
5.46 ± 0.13
LL
0.500 minimum
12.70 minimum
LS
0.100 ± 0.005
2.54 ± 0.13
S
0.200 ± 0.005
5.08 ± 0.13
A
0.120 ± 0.005
3.05 ± 0.13
B
0.040 ± 0.005
1.02 ± 0.13
C
0.120 ± 0.005
3.05 ± 0.13
DIMENSION
FIGURE 8 - TRIMMING TO VALUES
(Conceptual Illustration)
FIGURE 7 - TYPICAL RESISTANCE/
TEMPERATURE CURVE
+ 500
+ 400
+ 300
+ 200
+ 100
ΔR
0
R
(ppm)
- 100
- 200
Interloop Capacitance
Reduction in Series
0.05 ppm/°C
- 0.1 ppm/°C
- 300
- 400
Current Path
Before Trimming
0.1 ppm/°C
Mutual Inductance
Reduction due
to Change in
Current Direction
0.14 ppm/°C
- 0.16 ppm/°C
0.2 ppm/°C
- 500
- 55
- 25
0
+ 25
+ 60 + 75 + 100 + 125
Ambient Temperature (°C) and TCR Chord Slopes for
Different Temperature Ranges
Note
• The TCR values for < 100 are influenced by the termination
composition and result in deviation from this curve
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Current Path
After Trimming
Trimming Process
Removes this Material
from Shorting Strip Area
Changing Current Path
and Increasing
Resistance
Note: Foil shown in black, etched spaces in white
Document Number: 63239
Revision: 10-Mar-15
VHP4Z, VPR247Z
TABLE 4 - GLOBAL PART NUMBER INFORMATION
NEW GLOBAL PART NUMBER: Y1480400R000T9L (preferred part number format)
DENOTES PRECISION
VALUE
AER*
Y
R =
K = k
0 = standard
9 = lead (Pb)-free
1 - 999 = custom
Y
1
4
8
0
4
0
0
R
0
0
0
T
9
PRODUCT CODE
RESISTANCE TOLERANCE
PACKAGING
1479 = VHP4Z
1480 = VPR247Z
T = ± 0.01 %
Q = ± 0.02 %
A = ± 0.05 %
B = ± 0.1 %
C = ± 0.25 %
D = ± 0.5 %
L = bulk pack
L
FOR EXAMPLE: ABOVE GLOBAL ORDER Y1480400R000T9L:
TYPE: VPR247Z
VALUE: 400
ABSOLUTE TOLERANCE: ± 0.01 %
TERMINATION: lead (Pb)-free
PACKAGING: bulk pack
HISTORICAL PART NUMBER: VPR247ZT 400R T B (will continue to be used)
VPR247Z
T
400R
MODEL
TERMINATION
OHMIC VALUE
VHP4Z
VPR247Z
T = lead (Pb)-free
None = tin/lead alloy
400
T
RESISTANCE
TOLERANCE
T = ± 0.01 %
Q = ± 0.02 %
A = ± 0.05 %
B = ± 0.1 %
C = ± 0.25 %
D = ± 0.5 %
B
PACKAGING
B = bulk pack
Note
* For non-standard requests, please contact Application Engineering.
Document Number: 63239
Revision: 10-Mar-15
For any questions, contact
foil@vpgsensors.com
www.vishayfoilresistors.com
5
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Vishay Precision Group, Inc.
Disclaimer
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not limited to, the warranty expressed therein.
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Copyright Vishay Precision Group, Inc., 2014. All rights reserved.
Document No.: 63999
Revision: 15-Jul-2014
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