NXP Semiconductors SA58670A User Manual

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

Rev. 02 — 23 October 2008 Product data sheet

1. General description

The SA58670A is a stereo, ﬁlter-free class-D audio ampliﬁer which is available in an HVQFN20 package with the exposed Die Attach Paddle (DAP).

The SA58670A features independent shutdown controls for each channel. The gain may be set at 6 dB, 12 dB, 18 dB or 24 dB with gain select pins G0 and G1. Improved immunity to noise and RF rectiﬁcation is increased by high PSRR and differential circuit topology. Fast start-up time and small package makes it an ideal choice for both cellular handsets and PDAs.

The SA58670A delivers 1.4 W/channel at 5.0 V and 720 mW/channel at 3.6 V into 8 Ω. It delivers 2.1 W/channel at 5.0 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 SA58670A provides thermal and short-circuit shutdown protection.

2. Features

n Output power:

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 4 mm × 4 mm HVQFN20 package n Low junction to ambient thermal resistance of 24 K/W with exposed DAP

3. Applications

n Wireless and cellular handset and PDA n Portable DVD player n USB speaker n Notebook PC n Portable radio and gaming

u 2.1 W/channel into 4 Ω at 5.0 V u 1.4 W/channel into 8 Ω at 5.0 V u 720 mW/channel into 8 Ω at 3.6 V

NXP Semiconductors

n Educational toy

4. Ordering information

Table 1. Ordering information

Type number Package

SA58670ABS HVQFN20 plastic thermal enhanced very thin quad ﬂat package;

5. Block diagram

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

Name Description Version

SOT917-1

no leads; 20 terminals; body 4 × 4 × 0.85 mm

right input

left input

INRP INRN

n.c.

INLP

INLN

G0 G1

SDR

SDL

Refer to Table 6 for gain selection.

Fig 1. Block diagram

SA58670A

16 17

6, 10

20 19

15 1 8

300 kΩ

GAIN

ADJUST

GAIN

ADJUST

BIAS

CIRCUITRY

PWM

INTERNAL

OSCILLATOR

PWM

SHORT-CIRCUIT

PROTECTION

H-

BRIDGE

H-

BRIDGE

3, 13 PVDD

1411OUTRP

GND

2 5

9 AVDD

4, 12

002aad663

OUTRN

OUTLP OUTLN

PGND AGND

Product data sheet Rev. 02 — 23 October 2008 2 of 24

NXP Semiconductors

6. Pinning information

6.1 Pinning

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

terminal 1

index area

G1 G0

OUTLP OUTRP

PVDD PVDD

PGND

OUTLN

(1) Exposed Die Attach Paddle (DAP).

INLP

INLN

AGND

INRN

2019181716

115 214 313

SA58670ABS

412

(1)

DAP

511

n.c.

SDL

SDR

Transparent top view

AVDD

Fig 2. Pin conﬁguration for HVQFN20

6.2 Pin description

Table 2. Pin description

Symbol Pin Description

G1 1 gain select input 1 OUTLP 2 left channel positive output PVDD 3 power supply voltage (level same as AVDD) PGND 4 power ground OUTLN 5 left channel negative output n.c. 6 not connected SDL 7 left channel shutdown input (active LOW) SDR 8 right channel shutdown input (active LOW) AVDD 9 analog supply voltage (level same as PVDD) n.c. 10 not connected OUTRN 11 right channel negative output PGND 12 power ground PVDD 13 power supply voltage (level same as AVDD) OUTRP 14 right channel positive output G0 15 gain select input 0 INRP 16 right channel positive input INRN 17 right channel negative input AGND 18 analog ground

INRP

n.c.

PGND OUTRN

002aad664

Product data sheet Rev. 02 — 23 October 2008 3 of 24

NXP Semiconductors

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

Table 2. Pin description

Symbol Pin Description

INLN 19 left channel negative input INLP 20 left channel positive input

- (DAP) exposed die attach paddle; connect to ground plane heat spreader

7. Limiting values

Table 3. Limiting values

In accordance with the Absolute Maximum Rating System (IEC 60134).

Symbol Parameter Conditions Min Max Unit

P power dissipation derating factor 41.6 mW/K

amb

stg

esd

…continued

[1]

supply voltage Active mode −0.3 +6.0 V

Shutdown mode −0.3 +7.0 V

input voltage pin SDL GND V

SDR GND V

pin other pins −0.3 V

=25°C - 5.2 W

amb

=75°C - 3.12 W

amb

=85°C - 2.7 W

amb

DD DD DD

V V

+ 0.3 V

ambient temperature operating in free air −40 +85 °C junction temperature operating −40 +150 °C storage temperature −65 +85 °C electrostatic discharge

voltage

human body model ±2000 - V machine model ±200 - V

[1] VDD is the supply voltage on pins PVDD and pin AVDD.

GND is the voltage ground on pins PGND and pin AGND.

Product data sheet Rev. 02 — 23 October 2008 4 of 24

NXP Semiconductors

8. Static characteristics

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

Table 4. Static characteristics

=25°C; unless otherwise speciﬁed

amb

[1]

Symbol Parameter Conditions Min Typ Max Unit

DD(sd)

PSRR power supply rejection ratio V V

i(cm)

CMRR common mode rejection ratio inputs are shorted together;

v(cl)

supply voltage operating 2.5 - 5.5 V supply current VDD= 2.5 V; no load - 4 6 mA

= 3.6 V; no load - 5 7.5 mA

= 5.5 V; no load - 6 9 mA

shutdown mode supply current no input signal;

SDR=VSDL

= 2.5 V to 5.5 V - −75 −55 dB

= GND

- 10 1000 nA

common-mode input voltage 0.5 - VDD− 0.8 V

- −69 −50 dB

= 2.5 V to 5.5 V

HIGH-level input voltage VDD= 2.5 V to 5.5 V;

pins

SDL, SDR, G0, G1

LOW-level input voltage VDD= 2.5 V to 5.5 V;

pins

SDL, SDR, G0, G1

HIGH-level input current VDD= 5.5 V; VI=V

1.3 - V

0 - 0.35 V

--50 µA

LOW-level input current VDD= 5.5 V; VI=0V --5 µA switching frequency VDD= 2.5 V to 5.5 V 250 300 350 kHz closed-loop voltage gain VG0 = VG1 = 0.35 V 5.5 6 6.5 dB

= VDD; VG1 = 0.35 V 11.5 12 12.5 dB

= 0.35 V; VG1 = V

= VG1 = V

17.5 18 18.5 dB

23.5 24 24.5 dB

Pins OUTLP, OUTLN, OUTRP and OUTRN

DSon

O(offset)

o(sd)

drain-source on-state resistance VDD= 2.5 V - 700 - mΩ

= 3.6 V - 570 - mΩ

= 5.5 V - 500 - mΩ

| output offset voltage measureddifferentially;inputs

shutdown mode output impedance V

AC grounded; G V

= 2.5 V to 5.5 V

= V

SDR

= 0.35 V - 2 - kΩ

SDL

v(cl)

= 6 dB;

- 5 10 mV

[1] VDD is the supply voltage on pins PVDD and pin AVDD.

GND is the ground supply voltage on pins PGND and pin AGND.

Product data sheet Rev. 02 — 23 October 2008 5 of 24

NXP Semiconductors

9. Dynamic characteristics

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

Table 5. Dynamic characteristics

=25°C; RL=8Ω; unless otherwise speciﬁed

amb

[1]

Symbol Parameter Conditions Min Typ Max Unit

THD+N total harmonic

SVRR supply voltage ripple

CMRR common mode rejection

output power per channel; f = 1 kHz; THD+N = 10 %

=8Ω; VDD= 3.6 V - 0.72 - W

=8Ω; VDD= 5.0 V - 1.4 - W

=4Ω; VDD= 5.0 V - 2.1 - W

distortion-plus-noise

rejection

= 5.0 V; G

= 0.5 W - 0.11 - %

= 1.0 W - 0.14 - %

= 6 dB; f = 217 Hz

v(cl)

= 3.6 V - −73 - dB

= 5.0 V - −77 - dB

= 5.0 V; G

= 6 dB; f=1kHz

v(cl)

= 6 dB; f = 217 Hz - −69 - dB

v(cl)

ratio

d(sd-startup)

input impedance G

delay time from

= 6 dB - 28.1 - kΩ

v(cl)

= 12 dB - 17.3 - kΩ

v(cl)

= 18 dB - 9.8 - kΩ

v(cl)

= 24 dB - 5.2 - kΩ

v(cl)

VDD= 3.6 V - 3.5 - ms

shutdown to start-up

n(o)

output noise voltage VDD= 3.6 V; f = 20 Hz to 20 kHz;

inputs are AC grounded

no weighting - 35 - µV A weighting - 27 - µV

[1] VDD is the supply voltage on pins PVDD and pin AVDD.

Product data sheet Rev. 02 — 23 October 2008 6 of 24

NXP Semiconductors

10. Typical performance curves

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

THD+N

(%)

a. G

THD+N

(%)

−1

−2

−1

v(cl)

−5

=24dB

001aah484

(1)

(2) (3)

−4

−3

−2

−1

(1)

(2) (3)

Po (W)

10110

001aah485

−2

b. G

−5

v(cl)

= 6 dB.

−4

−3

−2

−1

Po (W)

10110

fi= 1 kHz. (1) VDD= 2.5 V. (2) VDD= 3.6 V. (3) VDD= 5.0 V.

Fig 3. Total harmonic distortion-plus-noise as a function of output power; RL=8Ω

Product data sheet Rev. 02 — 23 October 2008 7 of 24

NXP Semiconductors

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

THD+N

(%)

a. G

THD+N

(%)

−1

−2

−1

−5

v(cl)

=24dB.

001aah486

(1)

(2) (3)

−4

−3

−2

−1

(1)

Po (W)

(2) (3)

10110

001aah487

−2

b. G

−5

v(cl)

= 6 dB.

−4

−3

−2

−1

Po (W)

10110

fi= 1 kHz. (1) VDD= 2.5 V. (2) VDD= 3.6 V. (3) VDD= 5.0 V.

Fig 4. Total harmonic distortion-plus-noise as a function of output power; RL=4Ω

Product data sheet Rev. 02 — 23 October 2008 8 of 24

NXP Semiconductors

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

THD+N

(%)

−1

−2

−3

10 10

(1)

(2)

(3)

(1) Po = 350 mW; Vi = 590 mV (RMS). (2) Po = 240 mW; Vi = 490 mV (RMS). (3) Po = 120 mW; Vi = 346 mV (RMS).

a. RL=4Ω

THD+N

(%)

−1

(1)

(2)

001aah488

f (Hz)

001aah489

(3)

−2

−3

10 10

f (Hz)

(1) Po = 260 mW; Vi = 721.1 mV (RMS). (2) Po = 180 mW; Vi = 600 mV (RMS). (3) Po = 90 mW; Vi = 424.3 mV (RMS).

b. RL=8Ω

=6dB.

v(cl)

Fig 5. Total harmonic distortion-plus-noise as a function of frequency; VDD= 2.5 V

Product data sheet Rev. 02 — 23 October 2008 9 of 24

NXP Semiconductors

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

THD+N

(%)

−1

−2

−3

10 10

(1)

(3) (2)

(1) Po = 825 mW; Vi = 908.3 mV (RMS). (2) Po = 550 mW; Vi = 741.6 mV (RMS). (3) Po = 275 mW; Vi = 524.4 mV (RMS).

a. RL=4Ω

THD+N

(%)

−1

(1)

(2)

001aah490

f (Hz)

001aah491

−2

−3

10 10

(3)

f (Hz)

(1) Po = 560 mW; Vi = 1.058 V (RMS). (2) Po = 375 mW; Vi = 866 mV (RMS). (3) Po = 190 mW; Vi = 616.4 mV (RMS).

b. RL=8Ω

=6dB.

v(cl)

Fig 6. Total harmonic distortion-plus-noise as a function of frequency; VDD= 3.6 V

Product data sheet Rev. 02 — 23 October 2008 10 of 24

NXP Semiconductors

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

THD+N

(%)

−1

(1)

−2

−3

(2) (3)

10 10

(1) Po = 1.65 W; Vi = 1.285 V (RMS). (2) Po = 1.1 W; Vi = 1.05 V (RMS). (3) Po = 550 mW; Vi = 741.6 mV (RMS).

a. RL=4Ω

10 THD+N

(%)

−1

−2

(1)

(2) (3)

001aah492

f (Hz)

001aah493

−3

10 10

f (Hz)

(1) Po = 1.16 W; Vi = 1.523 V (RMS). (2) Po = 775 mW; Vi = 1.245 V (RMS). (3) Po = 380 mW; Vi = 871.8 mV (RMS).

b. RL=8Ω

=6dB.

v(cl)

Fig 7. Total harmonic distortion-plus-noise as a function of frequency; VDD= 5.0 V

Product data sheet Rev. 02 — 23 October 2008 11 of 24

NXP Semiconductors

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

−60

(dB)

−80

(1) (2)

−100

−120

(3)

(4)

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 8. Crosstalk (stepped all-to-one) as a function of frequency

−3

001aah495

001aah497

n(o)

(V)

−4

(1) (2)

−5

−6

10 10

(1) Left channel. (2) Right channel.

Fig 9. Noise output voltage (RMS value) as a function of frequency

f (Hz)

Product data sheet Rev. 02 — 23 October 2008 12 of 24

NXP Semiconductors

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

−60

(dB)

−80

−100

−120

2 20

(1) (2)

(3)

144 6 10 12 16 18

a. RL=4Ω

−60

(dB)

−80

001aah505

f (kHz)

001aah506

(1) (2)

−100

−120

2 20

(3)

144 6 10 12 16 18

b. RL=8Ω

(1) VDD = 2.5 V. (2) VDD = 3.6 V. (3) VDD = 5.0 V.

Fig 10. Crosstalk (one-to-one) as a function of frequency

f (kHz)

Product data sheet Rev. 02 — 23 October 2008 13 of 24

NXP Semiconductors

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

SDR; VSDL

001aah507

5 V

(V)

0321

3.6 V

2.5 V

Fig 11. Supply voltage as a function of shutdown

voltage

1600

(mA)

1200

001aah509

5.5

(mA)

4.5

3.5

2.5

2.5 5.54.53.5

001aah508

(1) (2)

(3)

VDD (V)

(1) left channel; RL=8Ω. (2) right channel; RL=4Ω. (3) right channel; RL=8Ω.

Fig 12. Supply current as a function of supply voltage

001aah510

(mA)

800

600

800

(1)

400

0 2.01.60.8 1.20.4

(2) (3)

(W)

a. RL=4Ω b. RL=8Ω

(1) VDD = 2.5 V. (2) VDD = 3.6 V. (3) VDD = 5.0 V.

Fig 13. Supply current as a function of output power

400

200

0 1.61.20.4 0.8

(1)

(2) (3)

(W)

Product data sheet Rev. 02 — 23 October 2008 14 of 24

NXP Semiconductors

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

0.8

(W)

0.6

0.4

0.2

0 2.01.60.8 1.20.4

(2)

(3)

001aah511

(1)

(W)

a. RL=4Ω b. RL=8Ω

(1) VDD = 5.0 V. (2) VDD = 3.6 V. (3) VDD = 2.5 V.

Fig 14. Power dissipation as a function of output power

100

(3)

(2)

001aah513

(1)

0.4

0.3

0.2

0.1

100

(3)

0 1.61.20.4 0.8

(3)

(2)

001aah512

(1)

(2)

(W)

001aah514

(1)

0 2.01.60.8 1.20.4

(W)

a. RL=4Ω b. RL=8Ω

(1) VDD = 5.0 V. (2) VDD = 3.6 V. (3) VDD = 2.5 V.

Fig 15. Output power efﬁciency as a function of output power

0 1.61.20.4 0.8

(W)

Product data sheet Rev. 02 — 23 October 2008 15 of 24

NXP Semiconductors

11. Application information

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

differential inputs

left channel

1 µF

INLP

OUTLP

OUTLN

PVDD

1 µF

PGND

1 nF

10 µF

1 µF

INLN

AGND

SA58670A

SDL SDR AVDD

differential inputs

right channel

1 µF

INRN

Fig 16. SA58670A application schematic

11.1 Power supply decoupling considerations

INRP

OUTRP

OUTRN

PVDD

PGND

1 µF

10 µF

1 nF

10 µF1 µF

002aad665

The SA58670A is a stereo class-D audio ampliﬁer that requires proper supply voltage decoupling to ensure the rated performance for THD+N and power efﬁciency. Todecouple high frequency transients, supply voltage spikes and digital noise on the supply voltage 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 SA58670A. It is important to place the decoupling capacitor at the supply voltage pins of the SA58670A because any resistance or inductance in the PCB trace between the SA58670A 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 supply voltage connection on the PCB to ﬁlter low frequency signals. Usually this is not required due to high PSRR of the SA58670A.

11.2 Input capacitor selection

The SA58670A 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 (V 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:

3dB–

----------------------------- -

2π Ri× Ci×

) range. If high-pass ﬁltering is

i(cm)

(1)

Product data sheet Rev. 02 — 23 October 2008 16 of 24

NXP Semiconductors

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 2 is solved for Ci:

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

--------------------------------------

2π Ri× f

3dB–

11.3 PCB layout considerations

Component location is very important for performance of the SA58670A. Place all external components very close to the SA58670A. Placing decoupling capacitors directly at the power supply voltage pins increases efﬁciency because the resistance and inductance in the trace between the SA58670A power supply voltage 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 pins (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.

(2)

For applications in which there are circuits that are EMI sensitive to low frequencies (< 1 MHz) and there are long leads from ampliﬁer to speaker,it is necessary to use an LC output ﬁlter.

Product data sheet Rev. 02 — 23 October 2008 17 of 24

NXP Semiconductors

11.5 Efﬁciency and thermal considerations

The maximum ambient operating temperature depends on the heat transferring ability of the heat spreader on the PCB layout. In Table 3 “Limiting values”, the power derating factoris given as 41.6 mW/K. The device thermal resistance, R power derating factor. Convert the power derating factor to R

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

is the reciprocal of the

th(j-a)

by Equation 3:

th(j-a)

th j-a()

----------------------------------------- -

derating factor

----------------

0.0416

For a maximum allowable junction temperature Tj= 150 °C and R maximum device dissipation of 1.5 W (750 mW per channel) and for 2.1 W per channel output power, 4 Ω load, 5 V supply, the maximum ambient temperature is calculated using

Equation 4:

amb max()Tj max()Rth j-a()Pmax

×()– 150 24 1.5×()– 114 °C===

The maximum ambient temperature is 114 °C at maximum power dissipation for 5 V supply and 4 Ω load. If the junction temperature of the SA58670A rises above 150 °C, the thermal protection circuitry turns the SA58670A 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 SA58670A HVQFN20 package incorporates an exposed DAP that is designed to solder the mount directly to the PCB heat spreader. By the use of thermal vias, the DAP 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.

24 K/W===

= 24 K/W and a

th(j-a)

(3)

(4)

12. Test information

15 µH

AP585

AUDIO

ANALYZER

INxP

INxN

Fig 17. Test circuit

Product data sheet Rev. 02 — 23 October 2008 18 of 24

DUT

POWER

SUPPLY

OUTxP

OUTxN

−

15 µH

LOW-PASS FILTER

MEASUREMENT

AUX0025

30 kHz

AP585

INPUTS

002aad417

NXP Semiconductors

2.1 W/channel stereo class-D audio ampliﬁer

13. Package outline

HVQFN20: plastic thermal enhanced very thin quad flat package; no leads; 20 terminals; body 4 x 4 x 0.85 mm

terminal 1 index area

SA58670A

SOT917-1

4.1

3.9

0 2.5 5 mm

2.45

2.15

(1)

4.1

2.45

3.9

2.15

REFERENCES

(1)

610

terminal 1 index area

DIMENSIONS (mm are the original dimensions)

(1)

UNIT

Note

1. Plastic or metal protrusions of 0.075 mm maximum per side are not included.

OUTLINE VERSION

SOT917 -1 MO-220- - - - - -

max.

0.05

0.00

0.30

0.18

20 16

0.2

IEC JEDEC JEITA

scale

0.51

detail X

0.6

0.4

0.1v0.05

0.05 0.1

EUROPEAN

PROJECTION

ACCB

ISSUE DATE

05-10-08 05-10-31

Fig 18. Package outline SOT917-1 (HVQFN20)

Product data sheet Rev. 02 — 23 October 2008 19 of 24

NXP Semiconductors

14. Soldering of SMD packages

This text provides a very brief insight into a complex technology. A more in-depth account of soldering ICs can be found in Application Note

soldering description”

14.1 Introduction to soldering

Soldering is one of the most common methods through which packages are attached to Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both the mechanical and the electrical connection. There is no single soldering method that is ideal for all IC packages. Wave soldering is often preferred when through-hole and Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not suitable for ﬁne pitch SMDs. Reﬂow soldering is ideal for the small pitches and high densities that come with increased miniaturization.

14.2 Wave and reﬂow soldering

Wave soldering is a joining technology in which the joints are made by solder coming from a standing wave of liquid solder. The wave soldering process is suitable for the following:

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

AN10365 “Surface mount reﬂow

• Through-hole components

• Leaded or leadless SMDs, which are glued to the surface of the printed circuit board

Not all SMDs can be wave soldered. Packages with solder balls, and some leadless packages which have solder lands underneath the body, cannot be wave soldered. Also, leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered, due to an increased probability of bridging.

The reﬂow soldering process involves applying solder paste to a board, followed by component placement and exposure to a temperature proﬁle. Leaded packages, packages with solder balls, and leadless packages are all reﬂow solderable.

Key characteristics in both wave and reﬂow soldering are:

• Board speciﬁcations, including the board ﬁnish, solder masks and vias

• Package footprints, including solder thieves and orientation

• The moisture sensitivity level of the packages

• Package placement

• Inspection and repair

• Lead-free soldering versus SnPb soldering

14.3 Wave soldering

Key characteristics in wave soldering are:

• Process issues, such as application of adhesive and ﬂux, clinching of leads, board

transport, the solder wave parameters, and the time during which components are exposed to the wave

• Solder bath speciﬁcations, including temperature and impurities

Product data sheet Rev. 02 — 23 October 2008 20 of 24

NXP Semiconductors

14.4 Reﬂow soldering

Key characteristics in reﬂow soldering are:

• Lead-freeversus SnPb soldering; note that a lead-free reﬂow process usually leads to

• Solder paste printing issues including smearing, release, and adjusting the process

• Reﬂow temperature proﬁle; this proﬁle includes preheat, reﬂow (in which the board is

Table 7. SnPb eutectic process (from J-STD-020C)

Package thickness (mm) Package reﬂow temperature (°C)

< 2.5 235 220 ≥ 2.5 220 220

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

higher minimum peak temperatures (see Figure 19) than a SnPb process, thus reducing the process window

window for a mix of large and small components on one board

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). In addition, the peak temperature must be 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 and 8

Volume (mm3) < 350 ≥ 350

Table 8. 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 19.

Product data sheet Rev. 02 — 23 October 2008 21 of 24

NXP Semiconductors

Fig 19. Temperature proﬁles for large and small components

maximum peak temperature

temperature

MSL: Moisture Sensitivity Level

= MSL limit, damage level

minimum peak temperature

= minimum soldering temperature

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

peak

temperature

time

001aac844

For further information on temperature proﬁles, refer to Application Note

“Surface mount reﬂow soldering description”

15. Abbreviations

Table 9. Abbreviations

Acronym Description

DAP Die Attach Paddle DVD Digital Video Disc EMI ElectroMagnetic Interference ESR Equivalent Series Resistance LC inductor-capacitor ﬁlter PC Personal Computer PCB Printed-Circuit Board PDA Personal Digital Assistant PWM Pulse Width Modulator USB Universal Serial Bus

16. Revision history

AN10365

Table 10. Revision history

Document ID Release date Data sheet status Change notice Supersedes

SA58670A_2 20081023 Product data sheet - SA58670A_1 Modiﬁcations:

SA58670A_1 20080220 Product data sheet - -

Product data sheet Rev. 02 — 23 October 2008 22 of 24

• Table 4 “Static characteristics”:

– added I

speciﬁcation

DD(sd)

NXP Semiconductors

17. Legal information

17.1 Data sheet status

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

Document status

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

[1][2]

Product status

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 haveno 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, expressedor 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

[3]

http://www.nxp.com.

Deﬁnition

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, conveyanceor implication of any license under any copyrights, patents or other industrial or intellectual property rights.

17.4 Trademarks

Notice: All referencedbrands, 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: salesaddresses@nxp.com

Product data sheet Rev. 02 — 23 October 2008 23 of 24

NXP Semiconductors

19. Contents

1 General description. . . . . . . . . . . . . . . . . . . . . . 1

2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

3 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

4 Ordering information. . . . . . . . . . . . . . . . . . . . . 2

5 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 2

6 Pinning information. . . . . . . . . . . . . . . . . . . . . . 3

6.1 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

6.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 3

7 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . . 4

8 Static characteristics. . . . . . . . . . . . . . . . . . . . . 5

9 Dynamic characteristics . . . . . . . . . . . . . . . . . . 6

10 Typical performance curves . . . . . . . . . . . . . . . 7

11 Application information. . . . . . . . . . . . . . . . . . 16

11.1 Power supply decoupling considerations . . . . 16

11.2 Input capacitor selection. . . . . . . . . . . . . . . . . 16

11.3 PCB layout considerations . . . . . . . . . . . . . . . 17

11.4 Filter-free operation and ferrite bead ﬁlters. . . 17

11.5 Efﬁciency and thermal considerations . . . . . . 18

11.6 Additional thermal information . . . . . . . . . . . . 18

12 Test information. . . . . . . . . . . . . . . . . . . . . . . . 18

13 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 19

14 Soldering of SMD packages . . . . . . . . . . . . . . 20

14.1 Introduction to soldering . . . . . . . . . . . . . . . . . 20

14.2 Wave and reﬂow soldering . . . . . . . . . . . . . . . 20

14.3 Wave soldering. . . . . . . . . . . . . . . . . . . . . . . . 20

14.4 Reﬂow soldering. . . . . . . . . . . . . . . . . . . . . . . 21

15 Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . 22

16 Revision history. . . . . . . . . . . . . . . . . . . . . . . . 22

17 Legal information. . . . . . . . . . . . . . . . . . . . . . . 23

17.1 Data sheet status . . . . . . . . . . . . . . . . . . . . . . 23

17.2 Deﬁnitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

17.3 Disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . . 23

17.4 Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . 23

18 Contact information. . . . . . . . . . . . . . . . . . . . . 23

19 Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

SA58670A

2.1 W/channel stereo class-D audio ampliﬁer

Please be aware that important notices concerning this document and the product(s) described herein, have been included in section ‘Legal information’.

For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: salesaddresses@nxp.com

Date of release: 23 October 2008

Document identifier: SA58670A_2

NXP Semiconductors SA58670A User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

1. General description

2. Features

3. Applications

4. Ordering information

5. Block diagram

6. Pinning information

6.1 Pinning

6.2 Pin description

7. Limiting values

8. Static characteristics

9. Dynamic characteristics

10. Typical performance curves

11. Application information

11.1 Power supply decoupling considerations

11.2 Input capacitor selection

11.3 PCB layout considerations

11.6 Additional thermal information

12. Test information

13. Package outline

14. Soldering of SMD packages

14.1 Introduction to soldering

14.3 Wave soldering

15. Abbreviations

16. Revision history

17. Legal information

17.1 Data sheet status

17.3 Disclaimers

17.4 Trademarks

18. Contact information

19. Contents