SA58671 1.2 W/channel stereo class-D audio amplifier Rev. 02 — 24 October 2008 Product data sheet 1. General description The SA58671 is a stereo, filter-free class-D audio amplifier which is available in a 16 bump WLCSP (Wafer Level Chip-Size Package). The SA58671 features independent shutdown controls for each channel. The gain can be set at 6 dB, 12 dB, 18 dB or 24 dB using G0 and G1 gain select pins. Improved immunity to noise and RF rectification is increased by high PSRR and differential circuit topology. Fast start-up time and very small WLCSP package makes it an ideal choice for both cellular handsets and PDAs. The SA58671 delivers 1.3 W/channel at 5 V and 720 mW/channel at 3.6 V into 8 Ω. It delivers 1.2 W/channel at 5 V into 4 Ω. The maximum power efficiency is excellent at 70 % to 74 % into 4 Ω and 84 % to 88 % into 8 Ω. The SA58671 provides thermal and short-circuit shutdown protection. 2. Features n Output power: u 1.2 W/channel into 4 Ω at 5 V u 1.3 W/channel into 8 Ω at 5 V u 720 mW/channel into 8 Ω at 3.6 V n Supply voltage: 2.5 V to 5.5 V n Independent shutdown control for each channel n Selectable gain: 6 dB, 12 dB, 18 dB and 24 dB n High SVRR: −77 dB at 217 Hz n Fast start-up time: 3.5 ms n Low supply current n Low shutdown current n Short-circuit and thermal protection n Space savings with 2.06 mm × 2.11 mm 16 bump WLCSP package n Low junction to ambient thermal resistance of 110 K/W with adequate heat sinking of WLCSP 3. Applications n n n n Wireless and cellular handsets and PDA Portable DVD player USB speaker Notebook PC SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier n Portable radio and gaming n Educational toy 4. Ordering information Table 1. Ordering information Type number SA58671UK Package Name Description Version WLCSP16 wafer level chip-size package; 16 bumps; 2.06 × 2.11 × 0.6 mm SA58671UK 5. Block diagram A2 SA58671 C4 INRP D1 right input INRN C1 PVDD PGND D3 OUTRP GAIN ADJUST HBRIDGE PWM D4 OUTRN INTERNAL OSCILLATOR left input INLP A1 INLN B1 A3 OUTLP GAIN ADJUST PWM HBRIDGE A4 OUTLN G0 C2 G1 B2 SDR B3 D2 300 kΩ BIAS CIRCUITRY SDL B4 AVDD SHORT-CIRCUIT PROTECTION C3 AGND 300 kΩ 001aah390 Refer to Table 6 for gain selection. Fig 1. Block diagram SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 2 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 6. Pinning information 6.1 Pinning bump A1 index area SA58671UK 1 2 3 4 A 1 2 3 4 B A INLP PVDD C B INLN G1 SDR SDL D C INRN G0 AGND PGND D INRP AVDD Transparent top view OUTLP OUTLN OUTRP OUTRN 001aah181 002aac868 Transparent top view. Fig 2. Pin configuration for WLCSP16 Fig 3. Bump mapping for WLCSP16 6.2 Pin description Table 2. Pin description Symbol Pin Description INLP A1 left channel positive input INLN B1 left channel negative input INRN C1 right channel negative input INRP D1 right channel positive input PVDD A2 power supply voltage (level same as AVDD) G1 B2 gain select input 1 G0 C2 gain select input 0 AVDD D2 analog supply voltage (level same as PVDD) OUTLP A3 left channel positive output SDR B3 right channel shutdown input (active LOW) AGND C3 analog ground OUTRP D3 right channel positive output OUTLN A4 left channel negative output SDL B4 left channel shutdown input (active LOW) PGND C4 power ground OUTRN D4 right channel negative output SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 3 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 7. Limiting values Table 3. Limiting values In accordance with the Absolute Maximum Rating System (IEC 60134). Symbol Parameter Conditions VDD supply voltage VI input voltage P power dissipation active mode shutdown mode Min Max Unit −0.3 +6.0 V −0.3 +7.0 V −0.3 VDD + 0.3 V derating factor 9.12 mW/K Tamb = 25 °C - 1.2 W Tamb = 75 °C - 690 mW Tamb = 85 °C - 600 mW Tamb ambient temperature operating in free air −40 +85 °C Tj junction temperature operating −40 +150 °C Tstg storage temperature −65 +85 °C [1] VDD is the supply voltage on pin PVDD and pin AVDD. SA58671_2 Product data sheet [1] © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 4 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 8. Static characteristics Table 4. Static characteristics Tamb = 25 °C; unless otherwise specified. Symbol Parameter Conditions Min Typ Max Unit VDD supply voltage operating 2.5 - 5.5 V IDD supply current VDD = 5.5 V; no load - 6 9 mA VDD = 3.6 V; no load - 5 7.5 mA VDD = 2.5 V; no load - 4 6 mA IDD(sd) shutdown mode supply current no input signal; VSDR = VSDL = GND - 10 1000 nA |VO(offset)| output offset voltage measured differentially; inputs AC grounded; Gv(cl) = 6 dB; VDD = 2.5 V to 5.5 V - 5 25 mV PSRR power supply rejection ratio VDD = 2.5 V to 5.5 V - −75 −55 dB Vi(cm) common-mode input voltage 0.5 - VDD − 0.8 V CMRR common mode rejection ratio inputs are shorted together; VDD = 2.5 V to 5.5 V - −69 −50 dB VIH HIGH-level input voltage VDD = 2.5 V to 5.5 V; pins SDL, SDR, G0, G1 1.3 - VDD V VIL LOW-level input voltage VDD = 2.5 V to 5.5 V; pins SDL, SDR, G0, G1 0 - 0.35 V IIH HIGH-level input current VDD = 5.5 V; VI = VDD - - 50 µA IIL LOW-level input current VDD = 5.5 V; VI = 0 V - - 5 µA RDSon drain-source on-state resistance VDD = 5.5 V - 500 - mΩ VDD = 3.6 V - 570 - mΩ VDD = 2.5 V - 700 - mΩ Zo(sd) shutdown mode output impedance VSDR = VSDL = 0.35 V - 2 - kΩ fsw switching frequency VDD = 2.5 V to 5.5 V 250 300 350 kHz Gv(cl) closed-loop voltage gain VG0 = VG1 = 0.35 V 5.5 6 6.5 dB VG0 = VDD; VG1 = 0.35 V 11.5 12 12.5 dB VG0 = 0.35 V; VG1 = VDD 17.5 18 18.5 dB VG0 = VG1 = VDD 23.5 24 24.5 dB SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 5 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 9. Dynamic characteristics Table 5. Dynamic characteristics Tamb = 25 °C; RL = 8 Ω; unless otherwise specified. Symbol Parameter Conditions Po output power per channel; f = 1 kHz; THD+N = 10 % THD+N SVRR total harmonic distortion-plus-noise supply voltage ripple rejection Min Typ Max Unit RL = 8 Ω; VDD = 5.0 V - 1.3 - W RL = 8 Ω; VDD = 3.6 V - 0.72 - W RL = 4 Ω; VDD = 5.0 V - 1.2 - W Po = 1 W - 0.14 - % Po = 0.5 W - 0.11 - % - −77 - dB VDD = 5.0 V; Gv(cl) = 6 dB; f = 1 kHz Gv(cl) = 6 dB; f = 217 Hz VDD = 5.0 V - −73 - dB CMRR common mode rejection VDD = 5.0 V; Gv(cl) = 6 dB; f = 217 Hz ratio - −69 - dB Zi input impedance Gv(cl) = 6 dB - 28.1 - kΩ Gv(cl) = 12 dB - 17.3 - kΩ Gv(cl) = 18 dB - 9.8 - kΩ Gv(cl) = 24 dB - 5.2 - kΩ - 3.5 - ms no weighting - 35 - µV A weighting - 27 - µV VDD = 3.6 V td(sd-startup) delay time from shutdown to start-up VDD = 3.6 V Vn(o) output noise voltage VDD = 3.6 V; f = 20 Hz to 20 kHz; inputs are AC grounded SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 6 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 10. Typical performance curves 001aah165 −60 αct (dB) −80 (1) (2) −100 (3) (4) −120 103 104 105 f (Hz) (1) VDD = 3.6 V; L channel to R channel (2) VDD = 3.6 V; R channel to L channel (3) VDD = 5.0 V; L channel to R channel (4) VDD = 5.0 V; R channel to L channel Fig 4. Crosstalk (stepped all-to-one) as a function of frequency 001aah164 10−3 Vn(o) (V) 10−4 (1) (2) 10−5 10-6 10 102 103 104 105 f (Hz) (1) Left channel (2) Right channel Fig 5. RMS output noise voltage as a function of frequency SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 7 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 001aah167 102 THD+N (%) (1) (2) (3) 10 1 10−1 10−2 10−5 10−4 10−3 10−2 10−1 1 10 Po (W) a. RL = 8 Ω 001aah168 102 THD+N (%) (1) (2) (3) 10 1 10−1 10−2 10−5 10−4 10−3 10−2 10−1 1 10 Po (W) b. RL = 4 Ω (1) VDD = 2.5 V (2) VDD = 3.6 V (3) VDD = 5.0 V Fig 6. Total harmonic distortion-plus-noise as a function of output power; Gv(cl) = 6 dB SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 8 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 001aah170 10 THD+N (%) (1) (2) 1 (3) 10−1 10−2 10−5 10−4 10−3 10−2 10−1 1 10 Po (W) a. VDD = 3.0 V 001aah169 10 THD+N (%) (1) (2) 1 (3) 10−1 10−2 10−5 10−4 10−3 10−2 10−1 1 10 Po (W) b. VDD = 3.6 V 001aah171 10 THD+N (%) (1) (2) 1 (3) 10−1 10−2 10−5 10−4 10−3 10−2 10−1 1 10 Po (W) c. VDD = 4.2 V (1) fi = 1 kHz (2) fi = 3 kHz (3) fi = 5 kHz Fig 7. Total harmonic distortion-plus-noise as a function of output power; RL = 8 Ω; Gv(cl) = 6 dB SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 9 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 001aah172 10 THD+N (%) 1 (1) 10−1 (2) (3) 10−2 10 102 103 104 105 f (Hz) a. RL = 8 Ω 001aah173 10 THD+N (%) (1) 1 10−1 (2) (3) 10−2 10 102 103 104 105 f (Hz) b. RL = 4 Ω (1) VI = 900 mV (2) VI = 725 mV (3) VI = 525 mV Fig 8. Total harmonic distortion-plus-noise as a function of frequency; VDD = 3.6 V SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 10 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 001aah174 20 FFT (dB) −20 −60 −100 −140 0 4 8 12 16 20 f (kHz) a. channel 1 001aah556 20 FFT (dB) −20 −60 −100 −140 0 4 8 12 16 20 f (kHz) b. channel 2 Fig 9. FFT spectrum as a function of frequency; fi = 1 kHz; VI = 0 dB; VDD = 3.6 V; RL = 8 Ω SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 11 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 001aah175 20 FFT (dB) −20 −60 −100 −140 0 4 8 12 16 20 f (kHz) a. channel 1 001aah557 20 FFT (dB) −20 −60 −100 −140 0 4 8 12 16 20 f (kHz) b. channel 2 Fig 10. FFT spectrum as a function of frequency; fi = 1 kHz; VI = −10 dB; VDD = 3.6 V; RL = 8 Ω SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 12 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 001aah176 20 FFT (dB) −20 −60 −100 −140 0 4 8 12 16 20 f (kHz) a. channel 1 001aah558 20 FFT (dB) −20 −60 −100 −140 0 4 8 12 16 20 f (kHz) b. channel 2 Fig 11. FFT spectrum as a function of frequency; fi = 1 kHz; VI = −20 dB; VDD = 3.6 V; RL = 8 Ω SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 13 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 001aah391 +20 001aah392 +20 FFT (dB) FFT (dB) −20 −20 −60 −60 −100 −100 −140 −140 0 8 16 24 0 8 f (kHz) 16 24 f (kHz) b. VI = −10 dB a. VI = 0 dB 001aah393 +20 FFT (dB) −20 −60 −100 −140 0 8 16 24 f (kHz) c. VI = −20 dB Fig 12. FFT spectrum as a function of frequency; fi = 3 kHz; VDD = 3.6 V; RL = 8 Ω SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 14 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 001aah177 80 ηpo (%) (1) 60 (2) 001aah179 100 ηpo (%) 80 (1) (2) 60 40 40 20 20 0 0 0 0.4 0.8 1.2 1.6 2.0 0 0.4 0.8 1.2 1.6 Po (W) Po (W) a. RL = 4 Ω b. RL = 8 Ω (1) VDD = 3.6 V (2) VDD = 5.0 V Fig 13. Output power efficiency as a function of output power 001aah178 1.0 P (W) 0.8 001aah573 0.4 P (W) (2) 0.3 (1) 0.6 (1) (2) 0.2 0.4 0.1 0.2 0 0 0 0.4 0.8 1.2 1.6 2.0 0 Po (W) a. RL = 4 Ω 0.4 0.8 1.2 1.6 Po (W) b. RL = 8 Ω (1) VDD = 3.6 V (2) VDD = 5.0 V Fig 14. Power dissipation as a function of output power SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 15 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 11. Application information differential inputs left channel 1 µF differential inputs right channel 1 µF 1 µF 1 µF VDD VDD INLP INLN G1 AGND INRN INRP G0 FB FB OUTLP OUTRP 1 nF 1 nF FB FB SA58671 OUTLN OUTRN 1 nF 1 nF VDD PVDD 10 µF 1 µF PGND SDL SDR AVDD VDD 1 µF 10 µF 001aah394 Fig 15. SA58671 application schematic 11.1 Power supply decoupling considerations The SA58671 is a stereo class-D audio amplifier that requires proper power supply decoupling to ensure the rated performance for THD+N and power efficiency. To decouple high frequency transients, power supply spikes and digital noise on the power bus line, a low Equivalent Series Resistance (ESR) capacitor of typically 1 µF is placed as close as possible to the PVDD pins of the device. It is important to place the decoupling capacitor at the power pins of the device because any resistance or inductance in the PCB trace between the device and the capacitor can cause a loss in efficiency. Additional decoupling using a larger capacitor, 4.7 µF or greater, may be done on the power supply connection on the PCB to filter low frequency signals. Usually this is not required due to high PSRR of the device. 11.2 Input capacitor selection The SA58671 does not require input coupling capacitors when used with a differential audio source that is biased from 0.5 V to VDD − 0.8 V. In other words, the input signal must be biased within the common-mode input voltage range. If high pass filtering is required or if it is driven using a single-ended source, input coupling capacitors are required. The 3 dB cut-off frequency created by the input coupling capacitor and the input resistors (see Table 6) is calculated by Equation 1: 1 f –3dB = -----------------------------2π × R i × C i (1) SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 16 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier Table 6. Gain selection G1 G0 Gain (V/V) Gain (dB) Input impedance (kΩ) LOW LOW 2 6 28.1 LOW HIGH 4 12 17.3 HIGH LOW 8 18 9.8 HIGH HIGH 16 24 5.2 Since the value of the input decoupling capacitor and the input resistance determined by the gain setting affects the low frequency performance of the audio amplifier, it is important to consider this during the system design. Small speakers in wireless and cellular phones usually do not respond well to low frequency signals, so the 3 dB cut-off frequency may be increased to block the low frequency signals to the speakers. Not using input coupling capacitors may increase the output offset voltage. Equation 1 is solved for Ci: 1 C i = -------------------------------------2π × R i × f –3dB (2) 11.3 PCB layout considerations Component location is very important for performance of the SA58671. Place all external components very close to the device. Placing decoupling capacitors directly at the power supply pins increases efficiency because the resistance and inductance in the trace between the device power supply pins and the decoupling capacitor causes a loss in power efficiency. The trace width and routing are also very important for power output and noise considerations. For high current terminals (PVDD, PGND and audio output), the trace widths should be maximized to ensure proper performance and output power. Use at least 500 µm wide traces. For the input pins (INRP, INRN, INLP and INLN), the traces must be symmetrical and run side-by-side to maximize common-mode cancellation. 11.4 Filter-free operation and ferrite bead filters A ferrite bead low-pass filter can be used to reduce radio frequency emissions in applications that have circuits sensitive to frequencies greater than 1 MHz. A ferrite bead low-pass filter functions well for amplifiers that must pass FCC unintentional radiation requirements for frequencies greater than 30 MHz. Choose a bead with high-impedance at high frequencies and very low-impedance at low frequencies. In order to prevent distortion of the output signal, select a ferrite bead with adequate current rating. For applications in which there are circuits that are EMI sensitive to low frequency (< 1 MHz) and there are long leads from amplifier to speaker, it is necessary to use an LC output filter. SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 17 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 11.5 Efficiency and thermal considerations The maximum ambient temperature depends on the heat transferring ability of the heat spreader on the PCB layout. In Table 3 “Limiting values”, power dissipation, the power derating factor is given as 9.12 mW/K. The device thermal resistance, Rth(j-a) is the reciprocal of the power derating factor. Convert the power derating factor to Rth(j-a) by Equation 3: 1 1 R th ( j-a ) = ------------------------------------------ = ------------------- = 110 K /W derating factor 0.00912 (3) For a maximum allowable junction temperature, Tj = 150 °C and Rth(j-a) = 110 K/W and a maximum device dissipation of 0.6 W (300 mW per channel) and for 1.2 W per channel output power, 4 Ω load, 5 V supply, the maximum ambient temperature is calculated using Equation 4: T amb ( max ) = T j ( max ) – ( R th ( j-a ) × P max ) = 150 – ( 110 × 0.60 ) = 84 °C (4) The maximum ambient temperature is 84 °C at maximum power dissipation for 5 V supply and 4 Ω load. If the junction temperature of the SA58671 rises above 150 °C, the thermal protection circuitry turns the device off; this prevents damage to IC. Using speakers greater than 4 Ω further enhances thermal performance and battery lifetime by reducing the output load current and increasing amplifier efficiency. 11.6 Additional thermal information The SA58671 16 bump WLCSP package ground bumps are soldered directly to the PCB heat spreader. By the use of thermal vias, the bumps may be soldered directly to a ground plane or special heat sinking layer designed into the PCB. The thickness and area of the heat spreader may be maximized to optimize heat transfer and achieve lowest package thermal resistance. 12. Test information 15 µH AP585 AUDIO ANALYZER INxP OUTxP RL DUT INxN OUTxN + 15 µH AUX0025 30 kHz LOW-PASS FILTER − POWER SUPPLY AP585 MEASUREMENT INPUTS 002aad417 Fig 16. Test circuit SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 18 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 13. Package outline WLCSP16: wafer level chip-size package; 16 bumps; 2.06 x 2.11 x 0.6 mm A B D SA58671UK bump A1 index area A2 A E A1 detail X e1 1/2 e C ∅v ∅w b e M M C A B C y D e C e2 B 1/2 e A 1 2 3 4 X 0 1 2 mm scale DIMENSIONS (mm are the original dimensions) UNIT A max A1 A2 b D E e e1 e2 v w y mm 0.64 0.26 0.22 0.38 0.34 0.34 0.30 2.08 2.04 2.13 2.09 0.5 1.5 1.5 0.01 0.04 0.02 OUTLINE VERSION REFERENCES IEC JEDEC JEITA EUROPEAN PROJECTION ISSUE DATE 07-10-11 07-10-17 SA58671UK Fig 17. Package outline WLCSP16 SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 19 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 14. Soldering of WLCSP packages 14.1 Introduction to soldering WLCSP packages This text provides a very brief insight into a complex technology. A more in-depth account of soldering WLCSP (Wafer Level Chip-Size Packages) can be found in application note AN10439 “Wafer Level Chip Scale Package” and in application note AN10365 “Surface mount reflow soldering description”. Wave soldering is not suitable for this package. All NXP WLCSP packages are lead-free. 14.2 Board mounting Board mounting of a WLCSP requires several steps: 1. Solder paste printing on the PCB 2. Component placement with a pick and place machine 3. The reflow soldering itself 14.3 Reflow soldering Key characteristics in reflow soldering are: • Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to higher minimum peak temperatures (see Figure 18) than a PbSn process, thus reducing the process window • Solder paste printing issues, such as smearing, release, and adjusting the process window for a mix of large and small components on one board • Reflow temperature profile; this profile includes preheat, reflow (in which the board is heated to the peak temperature), and cooling down. It is imperative that the peak temperature is high enough for the solder to make reliable solder joints (a solder paste characteristic) while being low enough that the packages and/or boards are not damaged. The peak temperature of the package depends on package thickness and volume and is classified in accordance with Table 7 Table 7. Lead-free process (from J-STD-020C) Package thickness (mm) Package reflow temperature (°C) Volume (mm3) < 350 350 to 2000 > 2000 < 1.6 260 260 260 1.6 to 2.5 260 250 245 > 2.5 250 245 245 Moisture sensitivity precautions, as indicated on the packing, must be respected at all times. Studies have shown that small packages reach higher temperatures during reflow soldering, see Figure 18. SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 20 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier maximum peak temperature = MSL limit, damage level temperature minimum peak temperature = minimum soldering temperature peak temperature time 001aac844 MSL: Moisture Sensitivity Level Fig 18. Temperature profiles for large and small components For further information on temperature profiles, refer to application note AN10365 “Surface mount reflow soldering description”. 14.3.1 Stand off The stand off between the substrate and the chip is determined by: • The amount of printed solder on the substrate • The size of the solder land on the substrate • The bump height on the chip The higher the stand off, the better the stresses are released due to TEC (Thermal Expansion Coefficient) differences between substrate and chip. 14.3.2 Quality of solder joint A flip-chip joint is considered to be a good joint when the entire solder land has been wetted by the solder from the bump. The surface of the joint should be smooth and the shape symmetrical. The soldered joints on a chip should be uniform. Voids in the bumps after reflow can occur during the reflow process in bumps with high ratio of bump diameter to bump height, i.e. low bumps with large diameter. No failures have been found to be related to these voids. Solder joint inspection after reflow can be done with X-ray to monitor defects such as bridging, open circuits and voids. 14.3.3 Rework In general, rework is not recommended. By rework we mean the process of removing the chip from the substrate and replacing it with a new chip. If a chip is removed from the substrate, most solder balls of the chip will be damaged. In that case it is recommended not to re-use the chip again. SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 21 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier Device removal can be done when the substrate is heated until it is certain that all solder joints are molten. The chip can then be carefully removed from the substrate without damaging the tracks and solder lands on the substrate. Removing the device must be done using plastic tweezers, because metal tweezers can damage the silicon. The surface of the substrate should be carefully cleaned and all solder and flux residues and/or underfill removed. When a new chip is placed on the substrate, use the flux process instead of solder on the solder lands. Apply flux on the bumps at the chip side as well as on the solder pads on the substrate. Place and align the new chip while viewing with a microscope. To reflow the solder, use the solder profile shown in application note AN10365 “Surface mount reflow soldering description”. 14.3.4 Cleaning Cleaning can be done after reflow soldering. 15. Abbreviations Table 8. Abbreviations Acronym Description DUT Device Under Test DVD Digital Video Disc EMI ElectroMagnetic Interference ESR Equivalent Series Resistance FFT Fast Fourier Transform LC inductor-capacitor filter PC Personal Computer PCB Printed-Circuit Board PDA Personal Digital Assistant PSRR Power Supply Rejection Ratio PWM Pulse Width Modulator USB Universal Serial Bus WLCSP Wafer Level Chip-Size Package 16. Revision history Table 9. Revision history Document ID Release date Data sheet status Change notice Supersedes SA58671_2 20081024 Product data sheet - SA58671_1 Modifications: • Table 4 “Static characteristics”: – added “IDD(sd), shutdown mode supply current” specification • SA58671_1 Updated soldering information 20071221 Product data sheet SA58671_2 Product data sheet - - © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 22 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 17. Legal information 17.1 Data sheet status Document status[1][2] Product status[3] Definition Objective [short] data sheet Development This document contains data from the objective specification for product development. Preliminary [short] data sheet Qualification This document contains data from the preliminary specification. Product [short] data sheet Production This document contains the product specification. [1] Please consult the most recently issued document before initiating or completing a design. [2] The term ‘short data sheet’ is explained in section “Definitions”. [3] The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status information is available on the Internet at URL http://www.nxp.com. 17.2 Definitions Draft — The document is a draft version only. The content is still under internal review and subject to formal approval, which may result in modifications or additions. NXP Semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall have no liability for the consequences of use of such information. Short data sheet — A short data sheet is an extract from a full data sheet with the same product type number(s) and title. A short data sheet is intended for quick reference only and should not be relied upon to contain detailed and full information. For detailed and full information see the relevant full data sheet, which is available on request via the local NXP Semiconductors sales office. In case of any inconsistency or conflict with the short data sheet, the full data sheet shall prevail. 17.3 Disclaimers General — Information in this document is believed to be accurate and reliable. However, NXP Semiconductors does not give any representations or warranties, expressed or implied, as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information. Right to make changes — NXP Semiconductors reserves the right to make changes to information published in this document, including without limitation specifications and product descriptions, at any time and without notice. This document supersedes and replaces all information supplied prior to the publication hereof. Suitability for use — NXP Semiconductors products are not designed, authorized or warranted to be suitable for use in medical, military, aircraft, space or life support equipment, nor in applications where failure or malfunction of an NXP Semiconductors product can reasonably be expected to result in personal injury, death or severe property or environmental damage. NXP Semiconductors accepts no liability for inclusion and/or use of NXP Semiconductors products in such equipment or applications and therefore such inclusion and/or use is at the customer’s own risk. Applications — Applications that are described herein for any of these products are for illustrative purposes only. NXP Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Limiting values — Stress above one or more limiting values (as defined in the Absolute Maximum Ratings System of IEC 60134) may cause permanent damage to the device. Limiting values are stress ratings only and operation of the device at these or any other conditions above those given in the Characteristics sections of this document is not implied. Exposure to limiting values for extended periods may affect device reliability. Terms and conditions of sale — NXP Semiconductors products are sold subject to the general terms and conditions of commercial sale, as published at http://www.nxp.com/profile/terms, including those pertaining to warranty, intellectual property rights infringement and limitation of liability, unless explicitly otherwise agreed to in writing by NXP Semiconductors. In case of any inconsistency or conflict between information in this document and such terms and conditions, the latter will prevail. No offer to sell or license — Nothing in this document may be interpreted or construed as an offer to sell products that is open for acceptance or the grant, conveyance or implication of any license under any copyrights, patents or other industrial or intellectual property rights. 17.4 Trademarks Notice: All referenced brands, product names, service names and trademarks are the property of their respective owners. 18. Contact information For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: [email protected] SA58671_2 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 02 — 24 October 2008 23 of 24 SA58671 NXP Semiconductors 1.2 W/channel stereo class-D audio amplifier 19. Contents 1 2 3 4 5 6 6.1 6.2 7 8 9 10 11 11.1 11.2 11.3 11.4 11.5 11.6 12 13 14 14.1 14.2 14.3 14.3.1 14.3.2 14.3.3 14.3.4 15 16 17 17.1 17.2 17.3 17.4 18 19 General description . . . . . . . . . . . . . . . . . . . . . . 1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Ordering information . . . . . . . . . . . . . . . . . . . . . 2 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Pinning information . . . . . . . . . . . . . . . . . . . . . . 3 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 3 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . . 4 Static characteristics. . . . . . . . . . . . . . . . . . . . . 5 Dynamic characteristics . . . . . . . . . . . . . . . . . . 6 Typical performance curves . . . . . . . . . . . . . . . 7 Application information. . . . . . . . . . . . . . . . . . 16 Power supply decoupling considerations . . . . 16 Input capacitor selection . . . . . . . . . . . . . . . . . 16 PCB layout considerations . . . . . . . . . . . . . . . 17 Filter-free operation and ferrite bead filters. . . 17 Efficiency and thermal considerations . . . . . . 18 Additional thermal information . . . . . . . . . . . . 18 Test information . . . . . . . . . . . . . . . . . . . . . . . . 18 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 19 Soldering of WLCSP packages. . . . . . . . . . . . 20 Introduction to soldering WLCSP packages . . 20 Board mounting . . . . . . . . . . . . . . . . . . . . . . . 20 Reflow soldering . . . . . . . . . . . . . . . . . . . . . . . 20 Stand off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Quality of solder joint . . . . . . . . . . . . . . . . . . . 21 Rework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Revision history . . . . . . . . . . . . . . . . . . . . . . . . 22 Legal information. . . . . . . . . . . . . . . . . . . . . . . 23 Data sheet status . . . . . . . . . . . . . . . . . . . . . . 23 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Contact information. . . . . . . . . . . . . . . . . . . . . 23 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Please be aware that important notices concerning this document and the product(s) described herein, have been included in section ‘Legal information’. © NXP B.V. 2008. All rights reserved. For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: [email protected] Date of release: 24 October 2008 Document identifier: SA58671_2