The device includes a fully monolithic vco and only

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Maxim’s website at www.maxim-ic.com. 1 MA X2140 G e n e r a l D e s c rip tio n T h e M A X 2 1 4 0 c o m p l e t e r e c e i v e r i s d e s i g n e d f or s a t e llit e d i g it a l a u d io r a d io s e rvi c e s (S D A R S). T h e d e vi c e i n c l u d e s a f u ll y m o n o lit h i c V C O a n d o n l y n e e d s a S A W a t t h e I F a n d a c r y s t a l t o g e n e r a t e t h e r e f e r e n c e fr e q u e n c y . 19-3123; Rev 3; 10/05 KIT ATION EVALU E BL AVAILA Complete SDARS Receiver The MAX2140 complete receiver is designed for satellite digital audio radio services (SDARS). The device includes a fully monolithic VCO and only needs a SAW at the IF and a crystal to generate the reference frequency. To form a complete SDARS radio, the MAX2140 requires only a low-noise amplifier (LNA), which can be controlled by a baseband controller. The small number of external components needed makes the MAX2140based platform the lowest cost and the smallest solution for SDARS. The receiver includes a self-contained RF AGC loop and baseband-controlled IF AGC loop, effectively providing a total dynamic range of over 92dB. Channel selectivity is ensured by the SAW filter and by on-chip monolithic lowpass filters. The fractional-N PLL allows a very small frequency step, making possible the implementation of an AFC loop. Additionally, the reference is provided by an external XTAL and on-chip oscillator. A reference buffer output is also provided. A 2-wire interface (I2C-bus compatible) programs the circuit for a wide variety of conditions, providing features such as: •Programmable gains Features o Integrated Receiver, Requires Only One SAW Filter o Self-Contained RF AGC Loop o Differential I/Q Interface o Complete Integrated Frequency Generation o Bias Supply for External LNAs o Overcurrent Protection o Low-Power Standby Mode o Very Small 44-Pin Thin QFN Package Ordering Information PART TEMP RANGE PIN-PACKAGE MAX2140ETH -40°C to +85°C 44 Thin QFN-EP* MAX2140ETH+ -40°C to +85°C 44 Thin QFN-EP* *EP = Exposed paddle. +Denotes lead-free package. Block Diagram/Pin Configuration + - + + - - BE4 •Lowpass filters tuning MAX2140 General Description r. A r e f e r e n c e b u f f e r re m e nt on th e b a s eor c a li b r a ti o n p ro c e a v a il a b l e i n a 7 m m  I2CA2 VCC_BE4 IF2QO- IF2QI- IF2QO+ IF2QI+ QOUT- QOUT+ 42 41 40 39 38 37 36 35 34 2 43 I CA 1 44 d own SCL B l o c k D i a g r a m /P i n C o n f i g u r a t i o n SDA a ti b l e ) p ro g r a m s t h e ti o n s , p ro v i d i n g f e a - XM TUNER VCC_FE0 1 33 VTUNE RFIN+ 2 32 VCCREG RFIN- 3 31 VCC_VCO MAX2140 VCC_FE1 4 RF AGC IFOUT+ 5 A p pli c a tio n s S e rv i c e s (S D A R S) 30 VCC_FE3 1/N Σ ∆ - MOD PFD CHP 1/R IFOUT- 6 28 LOCK RFAGC_C 7 27 VCC_A LPF VCC_FE2 8 HPF 26 VCC_D /4/8 QUAD AGCPWM 9 25 REFOUT IFIN+ 10 24 XTAL LPF HPF IFIN- 11 12 13 14 15 16 17 18 19 20 21 22 VCC_BE2 VCC_BE3 VINANT VOUTANT IF2IO- IF2II- IF2IO+ IF2II+ IOUT- IOUT+ 23 VCC_XTAL VCC_BE1 i m In t e g r a t e d Pro d u c t s , d C o m p a ni e s , c o n v e y s i g h t s t o u s e t h e s e c o mt h e s y s t e m c o n f orm s t o d b y P h ili p s . 29 CPOUT ACTUAL SIZE 7mm x 7mm Front E nd T h e fr o n t e n d o f t h e M A X 2 1 4 0 , w h i c h d o w n c o n v e rt s t h e R F s i g n a l t o I F , i s d e f i n e d fr o m t h e d i f f e r e n t i a l R F i n p u t s ( p i n s R F I N + a n d R F I N -) t o t h e o u t p u t ( p i n s I F O U T + a n d I F O U T-) t o t h e S A W f il t e r. T h e fr o n t e n d i n c l u d e s a s e l f- c o n t a i n e d a n a l o g R F A G C lo o p . T h e e n g a g e m e n t t hr e s h o l d o f t h e lo o p c a n b e p r o g r a m m e d f r o m - 3 5 d B m t o - 1 5 d B m r e f e rr e d t o t h e R F i n p u t i n 1 d B s t e p s u s i n g t h e R F 4–R F 0 p ro g r a m m i n g b it s . T h e ti m e c o n s t a n t o f t h e l o o p i s s e t e x t e rn a ll y b y t h e c a p a c it or c o n n e c t e d t o R F A G C _ C . T h e i m a g e r e j e c t f ir s t m i x e r e n s u r e s a g o o d i m a g e a n d h a lf I F r e j e c tio n . T h e fro n t- e n d g a i n c a n b e r e d u c e d b y p ro g r a m m i n g b it s P M 3–P M 0 o v e r a 2 2 d B r a n g e , w it h a s t e p o f 2 d B . T h i s a ll o w s t h e s e l e c ti o n s o f S A W filt e rs w it h d iff e r e n t i n s e rt i o n l o s s . T h e I F o ut p ut is n o min a lly 9 0 0Ω d iff e r e nti a lly a n d r e q uir e s p u l l u p i n d u c t o r s t o V C C , w h i c h c a n b e u s e d a s p a rt o f t h e m a t c h i n g n e t w ork t o t h e S A W f il t e r i m p e d a n c e . B a c k End T h e b a c k e n d , w h i c h d o w n c o n v e rt s t h e I F s i g n a l t o q u a d r a t ur e b a s e b a n d , i s d e f i n e d fro m t h e S A W f i l t e r i n p u t s ( p i n s I F I N + a n d I F I N -) t o t h e b a s e b a n d o u t p u t s ( p i n s I O U T + , I O U T-, Q O U T + , Q O U T-). T h e b a c k e n d c o nt a in s a n I F A G C lo o p , w hi c h is c...
View Full Document

This test prep was uploaded on 03/13/2014 for the course ECE 453 taught by Professor Staff during the Spring '08 term at University of Illinois, Urbana Champaign.

Ask a homework question - tutors are online