OIP3 (dBm) LT5554 Broadband Ultra Low Distortion 7-Bit Digitally Controlled VGA FEATURES DESCRIPTION n 1GHz Bandwidth at all Gains The LT 5554 is a 7-bit digitally controlled programmable n 48dBm OIP3 at 200MHz, 2V into 50, gain (PG) ampli er with 16dB gain control range. It P-P R = 100 consists of a 50 input variable attenuator, followed by OUT n 88dBc IMD3 at 200MHz, 2V into 50, a high linearity variable transconductance ampli er. The P-P R = 100 coarse 4dB input attenuator step is implemented via 2-bits OUT n 1.4nV/Hz Input-Referred-Noise (RTI) of digital control (PG5, PG6). The ne transconductance n 20dBm Output P1dB at 70MHz, R = 130 ampli er 0.125dB step within 3.875dB gain control range OUT n 2dB to 18dB Gain Range (R = 50) is set via 5-bits digital control (PG0 to PG4). The LT5554 OUT n 0.125dB Gain Step Size gain control inputs (PGx) and the STROBE input can be n 30ps Group Delay Variation directly coupled to TTL or ECL drivers. The seven parallel n 5ns Fast Gain Settling Time gain control inputs time skew can be eliminated by using n 5ns Fast Overdrive Recovery the STROBE input positive transition. n 80dB Reverse Isolation The internal output resistor R = 400 limits the maxi- O mum overall gain to 36dB for open outputs. The internal APPLICATIONS circuitry of open output collectors enables the LT5554 to be unconditionally stable over any loading conditions (in- n Differential ADC Driver cluding external SAW lters) and provides 80dB reverse n IF Sampling Receivers isolation at 300MHz. n VGA IF Power Ampli er n The LT5554 is internally protected during overdrive and 50 Driver n has an on-chip power supply regulator. Instrumentation L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other With 0.125dB step resolution and 5ns settling time, the trademarks are the property of their respective owners. LT5554 is suitable in applications where continuous gain control is required. TYPICAL APPLICATION OIP3 and SFDR vs Frequency 132 49 R = 50 OUT 5V V MODE CC 0.1F 130 46 + IN OIP3 IF IF RF DEC LT5554 BPF ADC AMPLIFIER BPF INPUT + IN 128 43 7 BITS LO 0.1F 5554 TA01 PGx GAIN CONTROL SFDR C DEC STROBE 0.1F 126 40 0 50 100 150 200 FREQUENCY (MHz) 5554 TA01b 5554f 1 SFDR (dBm/Hz)LT5554 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Notes 1, 2) TOP VIEW Supply Voltage V .......................................................................... 6V CC 32 31 30 29 28 27 26 25 Pin Voltages and Currents GND 1 24 V CC + OUT , OUT ............................................................7V GND 2 23 ENB STROBE, PGx ..........................................0.5V to V DEC GND CC 3 22 + ENB, MODE .............................................0.5V to V IN 4 21 OUT CC 33 + + IN 5 20 OUT IN , IN , DEC ........................................... 0.5V to 4V DEC 6 19 GND Operating Ambient Temperature Range GND 7 18 MODE LT5554 ............................................... 40C to +85C GND V 8 17 CC Junction Temperature ........................................... 125C 9 10 11 12 13 14 15 16 Storage Temperature Range ................. 65C to +150C UH PACKAGE 32-LEAD (5mm s 5mm) PLASTIC QFN T = 150C, = 34C/W, = 3C/W JMAX JA JC EXPOSED PAD (PIN 33) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT5554IUH PBF LT5554IUH TRPBF 5554 40C to 85C 32-Lead (5mm 5mm) Plastic QFN Consult LTC Marketing for parts speci ed with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: