ANJ_1092A

Transcription

1 Application Note SBAA066 ± ± ± ± µ ±

2 ± ± ± 24 Bits 20/24MSB 2 s f S 768 khz 25 MHz (1) V IH V (1) V IL V (2) V IH V (2) V IL V (1) I IH V IH = V DD ±10 µa (1) I IL V IL = 0V ±10 µa (2) I IH V IH = 0V ±10 µa (2) I IL V IL = V DD 100 µa THD N V O = 0dB U % U-J % U-K % V O = 20dB U % U-J % U-K % EIAJA UU-J db U-K db S/N EIAJA db f = 1002Hzat 90dB ±0.5 db ±1.0 ±3.0 % of FSR ±0.5 ±1.0 % of FSR 0 70 ±25 ppm of FSR/ 0 70 ±5 ppm of FSR/ ±1.2 ma 1.0 kω (±0.003% of FSR) 1.2mA(10Ω100Ω) 200 nsec : V CC = V DD V DC = V DD V DC : I CC V CC = V DD = 5.0V 5 8 ma I CC = V DD = 5.0V ma Ω ± 2

3 DGND V DD DATA BCLK 3 WCLK BandGap Reference /TRIM REF DC SERVO DC Level Shift 8 9 /MODE /20bit /INV Servo Amp 10 Digital Portion 4 V DD Bpo Amp 12 BPO DC Switch Driver Current Source Q 1 Q 2 Q 3 R e Q a Q b Q c R-2R R-2R 11 V CC 15,16 AGND 14 I OUT 20 3

4 ± 5V 2mA V DD V CC 3mA 0V DGND AGND 0V REF DC SRV DC BPO BPO DC I OUT DAC 20mA 10mA V DD 5V 4

5 V CC V CC AGND ±5V AGND R ±5V V DD V DD DGND DGND R V DD V DD ± ± ± ± V CC AGND V DD DGND V DD ±5V ±5V π µ µ µ ± ± µ 5

6 Ω V S f S A (96kHz 8) 6 = 28.95V/µs 1/2T S = 0.5 [1/(96kHz 8)] = 650nsec T S % of FSR V S T S T S T S T S T S A : F/S signal swing at 2Vrms = 6V OPA134 OPA627 OPA604 20V/µs 55V/µs 25V/µs 1µs 550ns 1.5µs T S = 1/f S = 1/(96kHz 8) = 1.3µsec 8 : 8 R O = 1K R F = 2.5K V no = (1 R F /R O ) V ni = 3.5V ni V ni is specified as noise density, Vn / BW(Hz) V n by OPA134 : 8nv/ BW(Hz) V n by OPA627 : 5.6nV/ BW(Hz) V n by OPA604 : 11nV/ BW(Hz) V ni V no BW = 20kHz, V ni V ni (OPA134) : 1.13µV V ni (OPA627) : 0.79µV V ni (OPA604) : 1.56µV V no V no (OPA134) : 3.96µV V no (OPA627) : 2.77µV V no (OPA604) : 5.46µV S(S = 2Vrms) / N(V no ) (A) S/N (OPA134) : 114.1dB!! S/N (OPA627) : 117.2dB!! S/N (OPA604) : 111.3dB!! R O : R F : I/V V ni : 6

7 ± S1 S OUT = S1 S2 = 2S N1 S2 N OUT = N1 2 N2 2 N2 7

8 S(1)rms THD N(1)rms DATA I/V OPA627 2 OPA2134 S OUT THD N OUT S(2)rms THD N(2)rms S OUT = S(1)rms S(2)rms = 2S [S(1) = S(2)] THD N OUT = THD N(1) 2 rms THD N(2) 2 rms THD N = 2 (THD N)2 rms 2S rms as THD N(1) = THD N(2) THD Nn THD N(n) = n n #1 THD N : % : 112.8dB SNR : 114.0dB (V OUT = 4Vrms, G = 1) THD N : % : 114.5dB SNR : 118.3dB #2 THD N : % : 111.5dB SNR : 114.0dB (V OUT = 2Vrms, G = 0.5) THD N : % : 113.5dB SNR : 116.0dB 8

9 S(1)rms THD N(1)rms (INV) I/V OPA627 DATA Ncm Balanced Amp OPA OPA2134 S OUT THD N D OUT NCM I/V OPA627 S(2)rms THD N(2)rms S OUT = S(2)rms [ S(1)rms] = 2Srms [ S(1) = S(2)] THD N D OUT = THD N D (2) 2 rms THD N D (1) 2 rms THD N D = 2 (THD N D )2 rms 2S rms N N CM = CM CMRR N D : N CM : CMRR : THD N D (n) = n n #1 THD N : % : 112.8dB SNR : 114.0dB (V OUT = 4Vrms, G = 1) THD N : % : 116.0dB SNR : 119.0dB Balance Amp (OPA2134) #2 THD N : % : 111.5dB SNR : 114.0dB (V OUT = 2Vrms, G = 0.5) THD N : % : 114.7dB SNR : 117.5dB 9

10 WCLK CLOCK DATA (INV) I/V OPA f S WCLK CLOCK DATA (INV) Balance Amp (OPA2134) WCLK CLOCK DATA WCLK CLOCK DATA I/V OPA627 10

11 5V Important DATA 1 BCLK WCLK Important I OUT GND pin Top layer Bottom layer 10 Bypass CAP 5V 14. Top layer () 5V line GND U 5V line I OUT I/V : (1) Bottom layer 15. (ANJ1092)

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