LTC6603 Dual Adjustable Lowpass Filter FEATURES DESCRIPTION n Guaranteed Phase and Gain Matching Specs The LTC 6603 is a dual, matched, programmable lowpass n Programmable BW Up to 2.5MHz lter for communications receivers and transmitters. The n Programmable Gain (0dB/6dB/12dB/24dB) selectivity of the LTC6603, combined with its linear phase, n 9th Order Linear Phase Response phase matching and dynamic range, make it suitable for n Differential, Rail-to-Rail Inputs and Outputs ltering in many communications systems. With 1.5 n Low Noise: 145dBm/Hz (Input Referred) phase matching between channels, the LTC6603 can be n Low Distortion: 75dBc at 200kHz used in applications requiring pairs of matched lters, n Simple Pin Programming or SPI Interface such as transceiver I and Q channels. Furthermore, the n Set the Max Speed/Power with an External R differential inputs and outputs provide a simple interface n Operates from 2.7V to 3.6V for most communications systems. n Input Range from 0V to 5.5V The sampled data lter does not require an external clock n 4mm 4mm QFN Package yet its cutoff frequency can be set with a single external resistor with an accuracy of 3.5% or better. The external resistor programs an internal oscillator whose frequency APPLICATIONS is divided prior to being applied to the lter networks. n Small/Low Cost Basestations: This allows up to three cutoff frequencies that can be IDEN, PHS, TD-SCDMA, CDMA2000, WCDMA, obtained for each external resistor value, allowing the UMTS cutoff frequency to be programmed over a range of more n Low Cost Repeaters, Radio Links, and Modems than six octaves. Alternatively, the cutoff frequency can n 802.11x Receivers be set with an external clock. The lter gain can also be n JTRS programmed to 1, 2, 4 or 16. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. The LTC6603 features a low power shutdown mode that can be programmed through the serial interface and is available in a 24-pin 4mm 4mm QFN package. TYPICAL APPLICATION 2.5MHz I and Q Lowpass Filter and Dual ADC 5V 3V LTC2297 100nH* 49.9 Phase Matching 0.1F 0.1F 180pF 10pF 60 I OUTPUT 14-BIT V = 3V, BW = 156.25kHz S ADC f = 125kHz, T = 25C A V+ V+ V+ IN A D 180pF 10pF 50 1000 UNITS 49.9 100nH* +INA +OUTA I IN 40 INA OUTA +INB +OUTB 100nH* 49.9 Q IN 30 LTC6603 INB OUTB R CLKIO 180pF 10pF BIAS 0.1F 20 Q OUTPUT 14-BIT 30.9k ADC V SER OCM 180pF 10pF 100nH* 49.9 10 0.1F V CM CAP CLKCNTL 3V 0 2.5 2 1.5 1 0.5 0 0.5 1 1.5 2 2.5 2.2F GAIN1 SDO MISMATCH (DEG) 6603 TA01b GAIN0 SDI GND LPFO 3V *COILCRAFT 0603HP GND LPF1 BASEBAND 6603 TA01a GAIN CONTROL 6603fa 1 UNITS (%)LTC6603 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V+ to GND ................................................................6V IN V+ , V+ to GND .........................................................4V A D V+ to V+ .............................................. 0.3V to +0.3V A D 24 23 22 21 20 19 Filter Inputs to GND ....................... 0.3V to V+ + 0.3V IN V+ 1 18 OUTA IN Pins 3, 4 to GND ............................. 0.3V to V+ + 0.3V A V+ 2 17 SER A Pins 5, 6, 9-11, V 3 16 V+ OCM D 25 15, 17, 21, 22 to GND .....................0.3V to V+ + 0.3V D R 4 15 CLKIO BIAS CLKCNTL 5 14 GND Output Short-Circuit Duration .......................... Inde nite LPF1(CS) 6 13 +OUTB Operating Temperature Range (Note 2) 7 8 9 10 11 12 LTC6603CUF .......................................40C TO 85C LTC6603IUF ........................................40C TO 85C Speci ed Temperature Range (Note 3) LTC6603CUF ...........................................0C TO 70C UF PACKAGE 24-LEAD (4mm 4mm) PLASTIC QFN LTC6603IUF ........................................40C TO 85C T = 150C, = 37C/W, = 4.3C/W JMAX JA JC EXPOSED PAD (PIN 25) IS GND. MUST BE SOLDERED TO THE PCB. Storage Temperature Range ................... 65C to 150C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LTC6603CUF PBF LTC6603CUF TRPBF 6603 0C to 70C 24-Lead (4mm 4mm) Plastic QFN LTC6603IUF PBF LTC6603IUF TRPBF 6603 40C to 85C 24-Lead (4mm 4mm) Plastic QFN Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *The temperature grade is identi ed by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: