Document Number: 63120

For any questions, contact: foil@vishay.com

www.vishay.com

Revision: 17-Jun-08

1

HZ Series (Z-Foil)

Vishay Foil Resistors

Hermetically Sealed Ultra High Precision Z-Foil Technology

Resistors with TCR of ± 0.2 ppm/°C, Tolerance of ± 0.001 % and

Load Life Stability of ± 0.005 %

Any value available within resistance range

INTRODUCTION

The Z-foil based oil filled, hermetically sealed

HZ-series

resistors represent an industry breakthrough. The hermetic

sealing eliminates the ingress of moisture and oxygen, while

the oil acts as a thermal conductor, thus eliminating long term

degradation elements of unsealed resistors, while at the

same time allowing the device to accept short periods of

overload without degradation.

The Z-foil technology provides a significant reduction of the

resistive components sensitivity to ambient temperature

variations (TCR) and applied power changes (PCR). When

combined with the hermetic sealing and oil filling, the

H-series resistors become the most precise and stable

resistors available.

With accuracies of ± 0.001 % and a resistance range from

5

Ω to 1.1 MΩ and long term shelf life of less than 2 ppm,

these devices are virtually secondary standards that can be

carried in sets for daily or periodic calibration of factory

measurement equipment.

The VHA series is also available with laboratory and

metrology level precision and long term stability with

additional in-house oriented process such as: special

TCR plotting, mounted chip stabilization, thermal shock

and bake prior to sealing, combined thermal shock and

power conditioning on finished product, thermal and

power conditioning, component linearity test.

Note

1. For lower TCR and for selected TCR tracking, please contact us

FEATURES

• Temperature coefficient of resistance (TCR):

± 0.2 ppm/°C typical (- 55 °C to + 125 °C,

+ 25 °C ref.)

• Power coefficient “ΔR due to self heating”:

5 ppm at rated power

• Tolerance: to ± 0.001 %

• Load life stability ± 0.002 % maximum ΔR (60 °C for

2000 h at 0.1 W per chip)

• Electrostatic discharge (ESD) > 25 000 V

• Resistance range: 5 Ω to 1.1 MΩ (higher or lower values of

resistance available)

• Power rating: 0.3 to 2.5 W at + 25 °C (depending on model

- see table 2)

• Shelf life stability: 2 ppm for at least 10 years

• Non inductive, non capacitive design

• Non hot spot design

• Rise time: 1.0 ns without ringing

• Current noise: < - 40 dB

• Thermal EMF: 0.05 µV/°C typical

• Voltage coefficient: < 0.1 ppm/V

• Non inductive: < 0.08 µH

• Terminal finishes available:

lead (Pb)-free

tin/lead alloy

• Impervious to harmful environments - oil filled

• For better performances, please contact us

TABLE 1 - TOLERANCE AND TCR VS.

RESISTANCE VALUE

RESISTANCE VALUE

(

Ω)

TYPICAL TCR AND

MAX. SPREAD

(- 55 °C to + 125 °C, + 25 °C ref.)

100 to < 1M1

± 0.2 ± 2

50 to < 100

± 0.2 ± 3

5 to < 50

± 0.2 ± 4

FIGURE 1 - TRIMMING TO VALUES

(Conceptual Illustration)

Mutual Inductance

Reduction due

to Opposing

Current in

Adjacent Lines

Current Path

Before Trimming

Note: Foil shown in black, etched spaces in white

Interloop Capacitance

Reduction in Series

Trimming Process

Removes this Material

from Shorting Strip Area

Changing Current Path

and Increasing

Resistance

Current Path

After Trimming