OUTPUT COUPLING CAPACITOR-LESS LOW VOLTAGE VIDEO AMPLIFIER WITH LPF

Transcription

1 OUTPUT COUPLING CAPACITOR-LESS LOW VOLTAGE VIDEO AMPLIFIER WITH LPF GENERAL DESCRIPTION The NJU7 is a Low Voltage Video Amplifier with LPF circuit. By the internal charge pump circuit, output capacitor is unnecessary. The NJU7 features low power and small package, and is suitable for low power design on downsizing of portable video system and system with video output. PACKAGE OUTLINE NJU7RB MSOP8(TVSP8) NJU7KU FEATURES Operating Voltage.5 to.5v Output coupling capacitor-less db amplifier Internal 75Ω Driver Circuit (-system drive) Internal LPF Power Save Circuit CMOS Technology Package Outline PIN CONFIGURATION db at.75mhz typ -db at 5MHz typ MSOP8(TVSP8)*, ESON8-U *MEET JEDEC MO-87-DA / THIN TYPE NJU7RB NJU7KU : CP : : VIN : Power Save 5: VOUT : 7: V- 8: CP BLOCK DIAGRAM db Amp. 75ohm Driver VIN Clamp.75MHz LPF VOUT V- Charge Pump POWER SAVE CP CP - -

2 ABSOLUTE MAXIMUM RATINGS (Ta=5 C) PARAMETER SYMBOL RATINGS UNIT Supply Voltage V +.55 V Power Dissipation P D MSOP8(TVSP8): 58 (Note) ESON8-U: 5 (Note) Operating Temperature Range Topr - to +85 C Storage Temperature Range Tstg -55 to +5 C (Note ) At on a board of EIA/JEDEC specification. (. x 7. x.mm layers, FR-) (Note ) Mounted on glass epoxy board. (.5.5.mm: based on EIA/JEDEC standard, Layers FR-, with Exposed Pad) (For Layers: Applying mm inner Cu area and a thermal via hole to a board based on JEDEC standard JESD5-5) mw RECOMMENDED OPEARATING CONDITION (Ta=5 C) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Operating Voltage Vopr V ELECTRICAL CHARACTERISTICS (V + =.V,R L =5Ω,Ta=5 C) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Operating Current I CC No Signal - ma Operating Current at Power Save Isave No Signal, Power Save Mode -. µa Maximum Output Voltage Swing Vom f=khz,thd=%.. - Vp-p Voltage Gain Low Pass Filter Characteristic Gv Vin=kHz,.Vp-p, Input Sine Signal 5... db Gfy.75M Vin=.75MHz/kHz,.Vp-p -.. Gfy5M Vin=5MHz/kHz,.Vp-p Differential Gain DG Vin=.Vp-p, step Video Signal % Differential Phase DP Vin=.Vp-p, step Video Signal deg S/N Ratio Switching Noise Level SNv Nswpl khz to MHz, Vin=.Vp-p % White Video Signal, R L =75Ω R L =75Ω, % White Video Signal input db db - 7 mvpp SW Change Voltage High Level VthPH Active.5 - V + SW Change Voltage Low Level VthPL Non-active -.5 V CONTROL TERMINAL PARAMETER STATUS NOTE Power Save H L OPEN Power Save: OFF Power Save: ON (Mute) Power Save: ON (Mute) - -

3 TERMINAL FUNCTION PIN PIN No. NAME FUNCTION EQUIVALENT CIRCUIT DC VOLTAGE CP Flying Capacitor Terminal - Power Supply - - VIN Input V V- Power Save Power Save - k V- 5 VOUT Output V 5k V- - -

4 PIN No. PIN NAME FUNCTION EQUIVALENT CIRCUIT DC VOLTAGE Ground V- V- Power Supply CP Flying Capacitor Terminal - V- - -

5 TEST CIRCUIT u CP CP 8 u +.u V- 7 u VIN 75Ω.u Powersave Vout 5 75Ω 75Ω - 5 -

6 APPLICATION CIRCUIT (Standard circuit) u CP CP 8 u +.u V- 7 u VIN.u Powersave Vout 5 75Ω APPLICATION CIRCUIT (Two-line drive circuit) u CP CP 8 u +.u V- 7 u VIN.u Powersave Vout 5 75Ω 75Ω - -

7 APPLICATION When coax multiplex transmission, we recommend that you adjust the output signal. Please refer to figure. (pin)=.v NJU7 Ro=75 to 8ohm to Video Input Coaxial Cable Rin=75ohm V-(pin7)=-V (=.x9%=-v) Rss=7ohm UTC Control Camera Side Control Box Side DC Sift Figure: How to shift the output DC signal The rare case, there is to be superimposed the directly DC control signal on the video signal when superimposed a control signal to the video signal by using a coaxial cable. In that case, the following symptoms will appear. - The control signal appears on the screen. - Loss of synchronization of the video signal Shows the proposed measures on the next page. A case of multiple coaxial transmission: UTC(Up The Coaxial) This is one of a case at the multiplex coaxial transmission used in CCTV. It is a system that control signals of camera multiplexing to the coaxial cable. This system is superimposed on the control signal pulse in the vertical blanking period as shown in Figure. This is because do not affect the video signal. Case of Coaxitron H H H Horizontal synchronization period Equalizing pulse period Vertical synchronization pulse period Equalizing pulse period Figure: A case of UTC - 7 -

8 Proposed measures is shift the output DC signal by using the V- terminal (pin 7) of NJU7. The steps are as follows:. A resistor: Rss add between the Ro (75Ω) and V- terminal (7pin).. Reduce Ro (75Ω). By adding a Rss, level of the video signal is attenuated. Example: Level of the video signal will be reduced 5% at connected Rss = 7Ω and Ro = 75Ω. Therefore, increase 5% of video output level by changed to 8Ω the Ro. *Table shows an external resistor value and the swing of video output signal at (pin) =.V, V.. Please evaluation of S/N. It is because the noise of the charge pump may change. Value (typ.) UNIT (pin). V V-(pin7) (*9%) V Termination resistance ohm Resistance (between Vss and Vout) 7 7 ohm Output resistance(ro) 8 8 ohm Sync. Voltage of Vout V Swing of Vout Vpp Table : external resistor value and the swing of video output signal at (pin) =.V, V

9 Case of -system 75ohm drive Shown in Figure, -system drive will be possible at system (75Ω for multiplex coaxial system) and system -(75Ω system for monitoring). However, shown in Figure, -system drive is not recommended, case of system and (75Ω for multiplex coaxial system) to Video Input (pin)=.v NJU7 75ohm 75ohm Ro=8ohm Coaxial Cable to Video Input Rin=75ohm V-(pin7)=-V (=.x9%=-v) Rss=7ohm Camera Side Control Box Side UTC Control Figure : Recommended -system drive circuit to Video Input (pin)=.v NJU7 75ohm 75ohm Ro=8ohm Coaxial Cable to Video Input Rin=75ohm V-(pin7)=-V (=.x9%=-v) Rss=7ohm X 7ohm UTC Control Camera Side Control Box Side Figure : Not recommended -system drive circuit - 9 -

10 TYPICAL CHARACTERISTICS Gain vs Frequency Gain [db] E+5.E+.E+7.E+8 Frequency [Hz] Icc vs Supply Voltage Isave vs Supply Voltage Icc [ma] 8 Isave [ma] Vom vs Supply Voltage Gv vs Supply Voltage Vom [Vpp] Gv [db]

11 TYPICAL CHARACTERISTICS Gf.75M vs Supply Voltage Gf5M vs Supply Voltage Gf.75M (db). Gf5M [db] Supply Voltage (V) DG vs Supply Voltage DP vs Supply Voltage DG [%].. DP [deg] SNv vs Supply Voltage Nswpl vs Supply Voltage SNv [db] Nswpl [mv]

12 TYPICAL CHARACTERISTICS VthH vs Supply Voltage VthL vs Supply Voltage VthH [V].8. VthL [V]

13 TYPICAL CHARACTERISTICS Idd vs Temp Isave vs Temp Idd (ma) Isave (ua) Temp vs Vom Temp vs Gv Vom (Vpp) Gv (db) Temp vs Gf.75M Temp vs Gf5M Gf.75M (db) Gf5M (db)

14 TYPICAL CHARACTERISTICS Temp vs DG Temp vs DP.5.5 DG (%).5 DP (deg) Temp vs SNv Temp vs Nswpl 7 SNv (db) Nswpl (mv) Temp vs VthH Temp vs VthL.5.5 VthH (V).5 VthL (V)

15 PACKAGE DIMENSIONS : MSOP8(TVSP8)*MEET JEDEC MO-87-DA / THIN TYPE - 5 -

16 PACKAGE DIMENSIONS (ESON8-U) [CAUTION] The specifications on this databook are only given for information, without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right - -