D E M O C IRC U IT 1 3 0 4 Q U IC K S TA RT G U ID E LTC 6 6 0 2 / LTC 6 6 0 3 P RO G RA M A B L E B A N D P A S S / L O W P A S S F IL T E R D E S C R IP T IO N Demonstration Circuit 1304A features tw o programmable filter ICs, the LTC6602 dual, matched, bandpass filter and the LTC6603,dual,matched,low pass filter. T h e L T C 6 6 0 2 B L O C K D IA G RA RA M DC1304A-- A is for an LTC6602 and The DC1304A DC1304A-- B is for an LTC6603. The DC1304A The LTC® 6602 is a dual, programmable bandpass filter and differential driver. The selectivity of the LTC6602 is ideal for filtering baseband tag signals in R FID systems. The LTC® 6603 is a dual, programmable low pass filter for communications receivers and transmitters in TD-SCDM A, W CDM A, CDM A2000, U M TS and 802.11x systems. A DC1304A-A or ---B board has tw o pairs of SM A connectors for differential inputs and tw o pairs of SM A connectors for differential outputs. The differential inputs can be AC coupled or DC coupled. O n board jumpers provide controlof an LTC6602 or an LTC6603. The jumper control settings are: serialor parallelcontrol, internalor externalclock, gain and bandw idth control and input AC or DC coupling. An on board multi-turn potentiometer sets the value of the R BIAS resistor that sets the IC pow er supply current and clock frequency. PCB turrets provide for board connections to an SPI master for a serialcontrolof IC gain and bandw idth. T h e L T C 6 6 0 3 B L O C K D IA RG A RA M LTC6602 features: G uaranteed Phase and G ain M atching Specs Programmable 5th O rder Low pass:40 kH z to 900 kH z Programmable 4th O rder H ighpass:4 kH z to 90 kH z Programmable G ain (0dB/12dB/24dB/30dB) Simple Pin Programming or SPI Interface Input R ange Extends from 0V to 5V Low Voltage O peration:2.7V to 3.6V Shutdow n and M ute M ode 4mm × 4mm Q FN Package LTC6603 features: G uaranteed Phase and G ain M atching Specs Programmable 9th O rder Low pass:24 kH z to 2.5 M H z Programmable G ain (0dB/6dB/12dB/24dB) Simple Pin Programming or SPI Interface Input R ange Extends from 0V to 5V Low Voltage O peration:2.7V to 3.6V Shutdow n M ode 4mm × 4mm Q FN Package Design Files for this circuit are available. Callthe LTC factory. ,LTC and LT are registered trademarks ofLinear Technology Corporation. DC1304 QUICK START GUIDE Q U ICK TEST SETU P – PAR ALLEL CO N TR O L Q U IC K T E S T P R O C E D U R E Test Proce Proce dure 1. Connect DC1304 as show n,turn on pow er and adjust the R BIAS1 pot for 50M H z. 2. 4. 6. Connect oscilloscope to VO UTA- and on the oscillo- Connect oscilloscope to VO UTB+ and on the oscilloscope display must show a 1Vp-p sinew ave. Connect oscilloscope to VO UTA+ and on the oscilloscope display must show a 1Vp-p sinew ave. Connect 50 ohm terminator to BIN-(J2) and sinew ave generator to BIN + (J1). Connect 50 ohm terminator to AIN-(J2) and sinew ave generator to AIN + (J1). 3. 5. 7. Connect oscilloscope to VO UTB- and on the oscilloscope display must show a 1Vp-p sinew ave. scope display must show a 1Vp-p sinew ave. 2 DC1304 QUICK START GUIDE LTC6602 FCLK AN D FCU TO FF R AN G E LTC6602 FCLK AN D FCU TO FF R AN G E FCLK R ange, 24M H z to 90M H z FCLK R ange, 12M H z to 80M H z RBIAS = (4.941 10^9) /FCLK;R BIAS in k RBIAS = (2.472 10^9) /FCLK;R BIAS in k Example:IfFCLK = 50 M H z Then Example:IfFCLK = 50 M H z Then RBIAS = (4.941 10^9) /(50 10^6) = 98.82k RBIAS = (2.472 10^9) /(50 10^6) = 49.44k The Low pass FCUTOFF = FCLK /N LP The Low pass FCUTOFF = FCLK /N LP The H ighpass FCU TO FF = FCLK /NH P NLP clock divider set by the (LPF1,LPF0) inputs. NLP and NH P are the clock dividers set by the (LPF1,LPF0) and (H PF1,H PF0) inputs respectively. LPF1 LPF0 NLP HPF1 HPF0 NHP 0 0 600 0 0 6000 0 1 300 0 1 2000 1 0 100 1 0 1000 1 1 100 1 1 Bypass HPF LPF1 LPF0 NLP 0 0 512 0 1 128 1 0 32 1 1 32 Low pass Filter FCU TO FF R ange NLP Low pass Filter FCU TO FF R ange Range 32 375kH z – 2.5M H z NLP Range 128 93.75kH z – 625kH z 100 240kH z – 900kH z 512 23.44kH z – 156.25kH z 300 80kH z – 300kH z 600 40kH z – 150kH z H ighpass Filter FCU TO FF R ange NHP Range 1000 24kH z – 90kH z 2000 12kH z – 45kH z 6000 4kH z – 15kH z 3 DC1304 QUICK START GUIDE 4 DC1304 QUICK START GUIDE 5 DC1304 QUICK START GUIDE 6 DC1304 QUICK START GUIDE 7