LC72121, 72121M, 72121V
• DO pin usage
The DO pin can be used for IF counter count completion checking and as an unlock detection output in addition to its
use in data output mode. It is also possible to have the DO pin reflect the state of an input pin to input that state to the
microcontroller.
• Power supply pins
Capacitors must be inserted between the power supply V and V pins for noise exclusion. These capacitors must be
DD
SS
placed as close as possible to the V and V pins.
DD
SS
• VCO setup
Applications must be designed so that the VCO (local oscillator) does not stop, even if the control voltage (Vtune) goes
to 0 V. If it is possible for the oscillator to stop, the application must use the control data (DLC) to temporarily force
Vtune to V to prevent deadlock from occurring. (Deadlock clear circuit)
CC
• Front end connection example
Since this product (and the LC72131 as well) is designed with the relatively high resistance of 200 kΩ for the pull-
down (on) resistors built in to the FMIN and AMIN pins, a common AM/FM local oscillator buffer can be used as
shown in the following circuit.
• PD pin
Note that the charge pump output voltage is reduced when this IC, which is a 3-V system, is used to replace the
LC72131, which is a 5-V system. This means that since the loop gain is reduced, the loop filter constants, the lock time
(SD wait time), and other related parameters must be reevaluated in the end product design.
■ No products described or contained herein are intended for use in surgical implants, life-support systems, aerospace
equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of
which may directly or indirectly cause injury, death or property loss.
■ Anyone purchasing any products described or contained herein for an above-mentioned use shall:
➀ Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and
distributors and all their officers and employees, jointly and severally, against any and all claims and litigation and all
damages, cost and expenses associated with such use:
➁ Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on
SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees
jointly or severally.
■ Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for
volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or implied
regarding its use or any infringements of intellectual property rights or other rights of third parties.
This catalog provides information as of July, 1998. Specifications and information herein are subject to change
without notice.
PS No. 5815-22/22
SANYO [ SANYO SEMICON DEVICE ]
