Sanyo LA7770 Specifications

Ordering number:ENN2208A

Monolithic Linear IC

LA7770

FSK Receiver for CATV Use

Overview

The LA7770 is a CATV-oriented wide-band FSK (frequency shift keying) receiver IC encapsulated in a DIP20S package that incorporates the functions required to demodulate scramble decoding data (i. e., the oscillator, mixer, lim-

iting IF amplifier, squelcher, and data shaper functions).

Features

•High limiting sensitivity.

•Incorporating a common-collector oscillator enables LC, crystal, or SAW-R (surface acoustic wave resonator) operated oscillations, as required by application.

Functions

•Mixer.

•Limiting IF amplifier.

•Squelch meter drive.

•Oscillator.

•Quadrature detector.

•Data shaper.

Package Dimensions

unit:mm
3021C-DIP20
			[LA7770]
			24.0
20			11
				7.62	6.4
					0.25
1			10
1.0
			(3.25)	3.9max
(0.57)	2.54		0.51min	3.3
		0.5	1.2
				SANYO : DIP20

Specifications

Maximum Ratings at Ta = 25˚C

Parameter	Symbol	Conditions	Ratings	Unit
Maximum supply voltage	VCC4 max		15	V
	VCC6 max		15	V
Maximum flow-out current	I18 max		3	mA
Allowable power dissipation	Pd max	Ta≤65˚C	770	mW
Operating temperature	Topr		–20 to +85	˚C
Storage temperature	Tstg		–55 to +125	˚C

Operating Conditions at Ta = 25˚C

Parameter	Symbol	Conditions	Ratings	Unit
Operating voltage range	VCC4		9 to 12	V
	VCC6		9 to 12	V
Comparator input voltage range	V16, V19		2V to (VCC–2V)	V

Any and all SANYO products described or contained herein do not have specifications that can handle applications that require extremely high levels of reliability, such as life-support systems, aircraft’s control systems, or other applications whose failure can be reasonably expected to result in serious physical and/or material damage. Consult with your SANYO representative nearest you before using any SANYO products described or contained herein in such applications.

SANYO assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges,or other parameters) listed in products specifications of any and all SANYO products described or contained herein.

SANYO Electric Co.,Ltd. Semiconductor Company

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN

13101TN (KT)/O0695TH (KOTO)/D088MO/O127TA, TS No.2208–1/7

LA7770

Operating Characteristics at Ta = 25˚C

Parameter	Symbol	Conditions		Ratings		Unit
			min	typ	max
Quiescent current	Icco	SQ-off	22	29	37	mA
Circuit current	ICC	SQ-on	23.0	30.5	39.0	mA
Mixer input capacitance	ci	100MHz		7		pF
Mixer input resistance	ri	100MHz		680		Ω
Mixer voltage gain	Vgm	RL=300Ω, 106.5M → 10.7M	9	12	15	dB
–3dB limiting sensitivity	Vi	F=±75kHz dev, at 1kHz		25	31	dB/µV
S/N	S/N	F=±75kHz dev, at 1kHz	47	55		dB
Total harmonic distortion	THD	F=±75kHz dev, at 1kHz		0.6	2	%
Demodulation output	Vo	F=±75kHz dev, at 1kHz	300	440	600	mVrms
AM rejection	AMR	AM : 30% at 1kHz	47	55		dB
Meter drive	ID	300µA → 600µA	5	12	20	µA/dB
Squelch threshold voltage	V14TH	DC	0.8	1.5	2.2	V
Data shaper input current	I16	DC		0.7	3.0	µA
Output saturation voltage	V18(sat)	I18=2mA		0.1	0.7	V
Duty	| TD |	f=14kHz		2.5	5.0	%

Equivalent Circuit Block Diagram

No.2208–2/7

LA7770

LA7770 Dynamic Behavior and Cautions on Designing

(1)Mixer

A double differential type mixer is employd with its input circuit configured as shown in Fig. 1, where the input signal is mixed with the oscillator output by its double differential circuit.

The mixed signal will be output from its open collector pin 5.

Fig. 1

Caution

a.Since an internal bias is applied to the input pin (pin 20), be sure to provide a DC blocking capacitor as shown in Fig. 2.

b.Connect the decoupling capacitor across pins 4 and 1 with the shortest possible wiring.

Fig. 2

(2)Oscillator

A common-collector oscillator is employed as shown in Fig. 3, and enables the LC, crystal, or SAW-R operated oscillations.

Fig. 3

No.2208–3/7