2.5V Video Amplifier with Reconstruction Filter

Transcription

1 ; Rev ; 5/5 2.5V Video Amplifier with Reconstruction Filter General Description The small, low-power video amplifier with integrated reconstruction filter operates from a supply voltage as low as 2.5V. The small size and the low minimum supply voltage make the ideal for portable applications such as mobile phones, digital still cameras, and camcorders. The DC-couples the input and the output, resulting in a very small solution. The input can be directly connected to the output of a video digital-toanalog converter (DAC). The reconstruction filter is implemented as a 4th-order Chebyshev with a minimum passband of 5.5MHz, 3dB attenuation at 8MHz, and 55dB attenuation at 27MHz. The output amplifier provides a closed-loop gain of +6dB () or +12dB (), and can drive a 2V P-P video signal into a 15Ω load to ground. The output signal is level-shifted so the sync tip is 1mV (typ) above ground. The operates from a 2.5V to 3.6V single supply and consumes only 5.3mA quiescent supply current. An active-low shutdown mode reduces the supply current to.1µa. The is available in tiny 6-pin µdfn (1mm x 1.5mm x.8mm) and 5-pin SC7 packages. The device is specified over the -4 C to +85 C extended temperature range. Mobile Phones/Smartphones Digital Still Cameras Portable Media Players Camcorders Applications Other Portable Video Amplifiers Features Tiny 6-Pin µdfn (1mm x 1.5mm x.8mm) and 5-Pin SC7 Packages DC-Coupled Input and Output Save Board Space 4-Pole Chebyshev Filter 5.5MHz Passband 55dB Attenuation at 27MHz.1µA Low-Current Shutdown Mode 2.5V to 3.6V Single-Supply Operation Video Amplifier with Fixed Gains of +6dB () or +12dB () PART* Ordering Information P-PACKAGE GA (db) TOP MARK EXK-T 5 SC ARV ELT-T 6 µdfn-6 (L611-1) +6 AU EXK-T 5 SC ARW ELT-T 6 µdfn-6 (L611-1) +12 AV *All devices are specified over the -4 C to +85 C operating temperature range. Typical Operating Circuit appears at end of data sheet. Pin Configurations PRODUCT FEATURES MAX953 MAX955 MAX49 DirectDrive, LPF, DC-coupled input/output, 5dB at 27MHz, TQFN DirectDrive, LPF, DC-coupled input/output, 5dB at 27MHz analog switch, TQFN Video amplifier, input clamp, µdfn, SOT23, SC7 TOP VIEW 6 N.C. V CC 5 4 GND MAX954 Video amplifier, 2 DC-coupled loads, optional DC offset bias, µdfn, SOT GND SHDN SHDN 3 4 V CC µdfn SC7 Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at , or visit Maxim s website at

2 ABSOLUTE MAXIMUM RATGS V CC to GND...-.3V to +4V SHDN,, to GND...-.3V to (V CC +.3V) Short-Circuit Duration to V CC, GND...Continuous Continuous Power Dissipation (T A = +7 C) 5-Pin SC7 (derate 3.1mW/ C above +7 C)...247mW 6-Pin µdfn (derate 2.1mW/ C above +7 C)...168mW Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. DC ELECTRICAL CHARACTERISTICS Operating Temperature Range...-4 C to +85 C Junction Temperature C Storage Temperature Range C to +15 C Lead Temperature (soldering, s)...+3 C (V CC = SHDN = 3., GND =, no load, T A = T M to T MAX, unless otherwise noted. Typical values are at T A = +25 C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS M TYP MAX UNITS Supply Voltage Range V CC Guaranteed by PSRR V Quiescent Supply Current I CC V =, 2.5V V CC 3.6V, SHDN = V CC ma Shutdown Supply Current I SHDN V SHDN =.1 1 µa Guaranteed by DC V CC = 2.5V 1.5 voltage gain () V CC = Input Voltage Range V Guaranteed by DC V CC = 2.5V.525 voltage gain () V CC = 3..6 Input Current I V = 3.5 µa Input Resistance R V / I 17 MΩ R DC Voltage Gain (Note 2) A L = 15Ω to GND, V V CC = 2.5V to 3V Output Sync-Tip Level V STIP Measured at, V =, R L = 15Ω to GND Output Voltage Swing Output Short-Circuit Current Threshold V, R L = 15Ω to GND, R L = 15Ω to GND V CC = 2.5V, V 1.5V V CC = 3., V 1.2V V CC = 2.5V, V.525V V CC = 3., V.6V V db 1 23 mv I SC Sourcing (Note 3) 95 ma Output Resistance R.15 Ω Shutdown Output Impedance R (OFF) V SHDN = 4 kω DC Power-Supply Rejection Ratio PSRR DC V =, 2.5V V CC 3.6V 5 9 db LOGIC PUTS (SHDN) Logic-Low Level V IL.8 V Logic-High Level V IH 2. V Logic Input Current I IL SHDN = GND and V CC 1 µa V P-P 2

3 AC ELECTRICAL CHARACTERISTICS (V CC = SHDN = 3., GND =, R L = 15Ω to GND, T A = +25 C, unless otherwise noted.) (Note 1) Passband Flatness PARAMETER SYMBOL CONDITIONS M TYP MAX UNITS V = 2V P-P, f = khz to 5.5MHz, flatness is referred to khz V f = 8MHz 3 Attenuation f = 2V P-P, attenuation is dt referred to khz f = 27MHz db Power-Supply Rejection Ratio PSRR f = khz 56 db Output Impedance Z V = 1.5V DC; f = 5MHz 2.5 Ω.4 Differential Gain Error DG NTSC, V = 2V P-P.4 db %.4 Differential Phase Error DP NTSC, V = 2V P-P.4 degrees 2T Pulse-to-Bar K Rating 2T = 25ns; bar time is 18µs; the beginning 2.5% and the ending 2.5% of the bar time are ignored.2 K% 2T Pulse Response 2T = 25ns.3 K% 2T Bar Response 2T = 25ns; bar time is 18µs; the beginning 2.5% and the ending 2.5% of the bar time are ignored.4 K% Nonlinearity 5-step staircase.4 % Line Time Distortion % Field Time Distortion % Group-Delay Variation (dϕ/dω) f = khz to 5.5MHz Peak Signal to RMS Noise SNR 3 3 V = 2V P-P, khz to 68 5MHz 65 ns db Enable Time t ON V SHDN = 3V, V settled to within 1% of the final voltage (V = 1V) (V =.5V) 8 8 ns Disable Time t OFF below 1% of the output V SHDN =, V settled to voltage (V = 1V) (V =.5V) ns Note 1: All devices are % production tested at T A = +25 C. Specifications over temperature limits are guaranteed by design. Note 2: DC voltage gain (A V ) is a two-point measurement in which the output voltage swing is divided by the input voltage swing. Note 3: Short-circuit current is the trip current for the protection. During the protection, is switched alternatively on and off. 3

4 (V CC = SHDN = 3., GND =, R L = 15Ω to GND.) SMALL-SIGNAL BANDWIDTH -5 V = mv P-P toc SMALL-SIGNAL BANDWIDTH -5 V = mv P-P Typical Operating Characteristics toc SMALL-SIGNAL GA FLATNESS V = mv P-P toc SMALL-SIGNAL GA FLATNESS V = mv P-P toc LARGE-SIGNAL BANDWIDTH -5 V = 2V P-P toc LARGE-SIGNAL BANDWIDTH -5 V = 2V P-P toc LARGE-SIGNAL GA FLATNESS 4 V = 2V P-P toc LARGE-SIGNAL GA FLATNESS V = 2V P-P toc8 DELAY (ns) GROUP DELAY toc9 4

5 Typical Operating Characteristics (continued) (V CC = SHDN = 3., GND =, R L = 15Ω to GND.) DELAY (ns) GROUP DELAY toc POWER-SUPPLY REJECTION RATIO toc11 POWER-SUPPLY REJECTION RATIO toc12 SUPPLY CURRENT (ma) SUPPLY CURRENT vs. TEMPERATURE TEMPERATURE ( C) toc13 SUPPLY CURRENT (ma) SUPPLY CURRENT vs. SHDN PUT VOLTAGE V SHDN = RISG SHDN PUT VOLTAGE (V) toc14 SHUTDOWN LOGIC THRESHOLD (V) SHUTDOWN LOGIC THRESHOLD vs. SUPPLY VOLTAGE V SHDN = RISG SUPPLY VOLTAGE (V) toc15 GA (db) VOLTAGE GA vs. TEMPERATURE TEMPERATURE ( C) toc16 GA (db) VOLTAGE GA vs. TEMPERATURE TEMPERATURE ( C) toc17 DIFFERENTIAL GA (%) DIFFERENTIAL PHASE (deg) DIFFERENTIAL GA AND PHASE toc18 5

6 Typical Operating Characteristics (continued) (V CC = SHDN = 3., GND =, R L = 15Ω to GND.) DIFFERENTIAL GA (%) DIFFERENTIAL GA AND PHASE toc19 2T RESPONSE toc2 2mV/div DIFFERENTIAL PHASE (deg) ns/div 4mV/div 2T RESPONSE toc21 MODULATED 12.5T RESPONSE toc22 mv/div 2mV/div 4mV/div 4mV/div ns/div 4ns/div MODULATED 12.5T RESPONSE toc23 NTC-7 COMPOSITE RESPONSE toc24 mv/div 5mV/div 4mV/div 4ns/div µs/div 6

7 Typical Operating Characteristics (continued) (V CC = SHDN = 3., GND =, R L = 15Ω to GND.) NTC-7 COMPOSITE RESPONSE toc25 MULTIBURST RESPONSE toc26 MULTIBURST RESPONSE toc27 25mV/div 5mV/div 25mV/div µs/div µs/div µs/div FIELD SQUARE-WAVE RESPONSE toc28 FIELD SQUARE-WAVE RESPONSE toc29 5mV/div 25mV/div 2ms/div 2ms/div Pin Description P µdfn SC7 NAME FUNCTION 1 1 Video Input 2 2 GND Ground 3 3 SHDN Active-Low Shutdown Input. Connect to GND to shutdown. 4 4 V CC Positive Power Supply 5 N.C. No Connection. Not internally connected. 6 5 Video Output 7

8 Detailed Description The filters and amplifies the video DAC output in applications such as digital still cameras and mobile phones. The consists of a lowpass filter and an output video buffer capable of driving a standard 15Ω video load to ground. The output buffer provides a fixed gain of +6dB, while the output buffer provides a fixed gain of +12dB. Filter The contains a 4th-order Chebyshev reconstruction filter. The Chebyshev-type response features a.4db flat passband for NTSC and PAL signals. The stopband offers 55dB (typ) of attenuation at 27MHz and above (see the Typical Operating Characteristics). Output Amplifier The features a +6dB gain, while the features a +12dB gain. Operating from a 2.5V to 3. supply, the output amplifier is able to drive a 2V signal into a 15Ω video load to ground. Operating from a 3. to 3.6V supply, the output amplifier is able to drive a 2.4V P-P signal into a 15Ω video load to ground. The output is typically offset 1mV above ground to guarantee linear operation of the amplifier. The output only sources current; all loads should be connected to ground. Short-Circuit Protection The typical application circuit includes a 75Ω back-termination resistor that limits short-circuit currents for an external short applied at the video output. The features internal output short-circuit protection to prevent device damage in prototyping and applications where the amplifier output can be directly shorted. Short-circuit protection activates if the output is short-circuited and the output current exceeds 95mA. During short-circuit protection, the output of the is shut off for 12µs and then turns on for.8µs. If the short is still present, the output shuts off again. Extended short circuits result in a pulsed output. The device resumes normal operation after the short is removed. Applications Information Input Considerations The input is DC-coupled. When the supply voltage is between a 2.5V and 3V supply, the input voltage range extends from ground to 1.5V for the and from ground to.525v for the. When the supply voltage is between 3V and 3.6V, the input voltage range extends from ground to 1.2V for the and from ground to.6v for the. The accepts a composite video signal with a sync tip from to 5mV and the accepts a composite video signal with a sync tip from to 25mV. A typical current-output DAC that operates from a single supply usually creates a composite video signal with a sync tip very close to ground. Hence, the DAC output can be directly connected to the input. Keep the board trace as short as possible to minimize parasitic stray capacitance and prevent unintentional high-frequency attenuation. Output Considerations The output must be DC-coupled. No AC-coupling capacitors are allowed. The connects directly to the video cable through a 75Ω series backtermination resistor. The other end of the cable should be properly terminated with a 75Ω resistor as well. Because of this configuration, the peak-to-peak amplitude as well as the DC level of the signal is divided by two. The output signal is level-shifted up so the sync tip is around 1mV. Power-Supply Bypassing and Layout Considerations The operates from a single-supply voltage down to 2.5V, allowing for low-power consumption. Bypass V CC to GND with a.1µf capacitor. Place all external components as close to the device as possible. ON OFF VIDEO ASIC VIDEO DAC SHDN SHUTDOWN CIRCUIT LOWPASS FILTER PROCESS: BICMOS Typical Operating Circuit GND V CC GA = +6dB GA = +12dB VIDEO AMP.1µF 75Ω Z = 75Ω 75Ω TELEVISION Chip Information 8

9 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to TOPMARK 2 P 1 DEX AREA AAA E A L 4 3 e 5 b 6 P 1.75x45 L2 6L UDFN.EPS 1 D A1 L1 3 2 A A 1 TOP VIEW SIDE VIEW BOTTOM VIEW b SECTION A-A COMMON DIMENSIONS M. NOM. MAX. A A D E L L L b e.5 BSC. -DRAWG NOT TO SCALE- TITLE: PACKAGE LE, 6L udfn, 1.5x1.x.8mm C 1 APPROVAL DOCUMENT CONTROL NO. REV. 9

10 Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to SC7, 5L.EPS PACKAGE LE, 5L SC C 1 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 12 San Gabriel Drive, Sunnyvale, CA Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.