Hitachi, Ltd.(NYSE:HIT) today announced the release
of the HVC321B variable-capacitance diode for use
in VCR tuners that features the industry's first 10V drive voltage. Sample shipments will begin in September
1998 in Japan. Reducing the drive voltage from 25V to
10V has made it possible to use the (approximately 12V) supply voltage of a VCR set directly, eliminating the need for a step-up DC-DC converter. At the same time,
the previous high capacitance ratio (C1/C10 > 10.5 ) has been maintained, enabling lower-cost, energy-saving tuner sets to be produced.
Since most variable-capacitance diodes used in the electronic tuning circuits of TV and VCR tuners employ
a 25V drive, when these diodes are used in VCR
tuners, a DC-DC converter is necessary to step up the VCR's maximum supply voltage to 25V. Meanwhile, the current trend is toward a demand for lower-voltage operation in line with EMC*stipulations etc., requiring significantly lower overall set cost and improved energy-saving features.
In response to these needs Hitachi has developed the HVC 321B variable-capacitance diode, offering a low-voltage drive together with a performance equal to that of previous products. Employing Hitachi's super shallow
pn junction process technology, the HVC321B is the industry's first VCR tuner variable-capacitance diode
to achieve a 10V low-voltage drive, through optimization of the epitaxial wafer specifications and process conditions. In addition, the same high capacitance ratio
(C1/C10 > 10.5) of previous products has been
maintained, while reducing capacitance deviation by approximately 30% compared with Hitachi's HVC306A. At the same time, low loss has been achieved,
with a high-frequency series resistance of 1 or less (at VR = 5V, f = 470MHz).
A small, thin UFP1608 package is used (Hitachi package code, compliant with EIAJ package code SC-79), allowing high-density
mounting. As well as VCR tuners, possible applications
include VCO/VCXO units requiring low-voltage operation and FM reception in car tuners. Hitachi will continue to develop new low-voltage-drive variable-capacitance diodes to further enhance the product lineup.
Note* EMC: Electromagnetic compatibility
Typical Applications
VCR electronic tuner circuits
VCO/VCXO oscillation tuner circuits
FM tuner electronic tuner circuits
Price
| Product Name | Sample Price |
| HVC321B | 8 Yen |
Specifications
| 1. Absolute Maximum Ratings (Ta = 25 degrees Celcius) |
| Item | Symbol | Value | Unit |
| Reverse voltage | VR | 15 | V |
| Junction temperature | Tj | 125 | degree Celcius |
| Storage temperature | Tstg | -55 to +125 | degree Celcius |
| 2. Electrical Characteristics (Ta = 25 degrees Celcius) |
| Item | Symbol | Min | Max | Unit | Test Conditions |
| Reverse current | IR1 | - | 10 | nA | VR=15V |
| IR2 | - | 100 | VR=15V, Ta=60 degrees Celcius |
| Capacitance | C1 | 29.0 | 33.0 | pF | VR=1V, f=1MHz |
| C10 | 2.55 | 2.90 | VR=10V, f=1MHz |
| Capacitance ratio | n | 10.5 | - | - | C1 / C10 |
| Series resistance | rS | - | 1.0 |  | VR=5V, f=470MHz |
| Matching error |  C/C* | - | 2.0 | % | VR=1 to 10V, f=1MHz |
Note* C.C system (Continuous Connected taping system) enable to make any 10 pcs of C/C continuous in a reel, expect extension to another group.
Calculate Matching Error; C/C = (Cmax - Cmin) / Cmin x 100 (%)
WRITTEN BY Secretary's Office
All Rights Reserved,
Copyright (C)
1998, Hitachi, Ltd.
