SM6801A Class-D Mono Amplifier for Portable Device
OVERVIEW
The SM6801A is an analog-input, class-D mono amplifier. Class-D operation provides high efficiency and low power consumption. The device also incorporates an original real-time operation dynamic range compression function that effectively suppresses the distortion in the saturation level region output by soft-clipping, boosting the average sound pressure from the speaker during playback. It also incorporates an input equalizer pin for output speaker frequency characteristics adjustment. These features make the device ideal for use in mobile telephones and speaker applications requiring miniaturization and high-efficiency. The output stage has a BTL output configuration where the output waveform inverts only the modulation components, enabling direct drive connection, without using an LC filter, to a dynamic speaker. The device is available in miniature 16-pin QFN packages, and requires only a peripheral chip capacitor to form a miniature amplifier circuit.
FEATURES
I
PINOUT
(Top view)
OUTP VSS2 OUTN VDD3 VDD4 PDWN VDD2 MUTEN DRCN VDD1 VREF1 IN TESTN VSS1 EQN EQP
I
I
I I
I I
Operating supply voltage • VDDS = 2.0 to 3.6V (input, logic) • VDDP = 2.0 to 5.5V (output) Low current consumption: 4.2mA (VDD = 3.6V) 1.6mA (VDD = 2.4V) Output power: 0.7W (VDD = 3.6V, 8Ω load) 0.28W (VDD = 2.4V, 8Ω load) Output fundamental frequency: 125kHz Gain • 6dB (Normal) • 15dB to 6dB automatic adjustment in response to the input level (Dynamic range compression mode) Silicon-gate CMOS process Package: 16-pin QFN
PACKAGE DIMENSIONS APPLICATIONS
I I I
(Unit: mm)
Cellular phone PDA Digital still camera
A
TOP VIEW 3.0 ± 0.08 B
BOTTOM VIEW 1.8 3 = 1.5 ± 0.05
3.0 ± 0.08
0.3 ± 0.1
ORDERING INFORMATION
Device SM6801AB Package
0.5
1.8 C 0.3 0.22 ± 0.05
0.02 S A B 0.1 ± 0.05
φ 0.05 M S A B
16-pin QFN
S
0.2 S
0.2 ± 0.05
0.05 S 0.5
0.7 ± 0.05
SEIKO NPC CORPORATION —1
SM6801A
BLOCK DIAGRAM
DRCN MUTEN PDWN
EQP
EQN
TESTN
VDD4
IN
− +
LEVEL SHIFTER PWM Modulator
BUFFER
OUTP VSS2
− +
LEVEL SHIFTER
BUFFER
OUTN
VREF1
BIAS VREF
OSC
MUTE, POWER DOWN, PROTECTION
VSS1 VDD1 VDD2
VDD3
PIN DESCRIPTION
Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Name*1 DRCN VDD1 VREF1 IN EQP EQN VSS1 TESTN VDD3 OUTN VSS2 OUTP VDD4 PDWN VDD2 MUTEN I/O*2 I – – I I I – Ip I O – O – I – I Function Dynamic range compression mode setting (HIGH: normal operation, LOW: DRC mode) Supply (input system) Reference voltage 1 (bias voltage) Signal input Equalizer network connection Equalizer network connection Ground (input system) Test pin (HIGH: normal operation, LOW: test mode) Supply (OUTN stage) Speaker minus (–) output Ground (output stage) Speaker plus (+) output Supply (OUTP stage) Power-down control (active LOW) Supply (logic system) Mute control (active LOW)
*1. VDDS = VDD1, VDD2, VDDP = VDD3, VDD4, VSS = VSS1, VSS2 *2. Ip = input pin with built-in pull-up resistor
SEIKO NPC CORPORATION —2
SM6801A
SPECIFICATIONS
Absolute Maximum Ratings
Parameter Symbol VDDS Supply voltage range VDDP VSS Input voltage range Storage temperature range Output current Power dissipation VIN TSTG IO PD Rating −0.3 to 4.6 −0.3 to 7.0 0 VSS − 0.3 to VDDS + 0.3 −55 to 125 300 1280 (Ta = 25°C)*1 Unit V V V V °C mA mW
*1. When mounted on a 3.5cm × 3.5cm board, the power dissipation is related to the operating temperature by the following equation.
I I I
Maximum junction temperature: TMAX = 125°C Operating ambient temperature: Ta = [°C] Thermal resistance: θJ = 78.0°C/W
PD =
(TMAX − Ta) θJ
1.4 1.2 Power dissipation [W] 1.02 1 0.8 0.6 0.4 0.2 0 25 35 45 55 65 75 85 Operating temperature [°C] 0.76 0.51
1.28
Recommended Operating Conditions
VSS = VSS1 = VSS2 = 0V, VDDS = VDD1 = VDD2, VDDP = VDD3 = VDD4 unless otherwise noted.
Parameter Supply voltage 1 Supply voltage 2 Supply voltage difference Operating ambient temperature Symbol VDDS VDDP VDD3 − VDD4 Ta Rating 2.0 to 3.6 2.0 to 5.5 ± 0.1 −40 to 85 Unit V V V °C
Note. VDDP ≥ VDDS VDDS and VDDP should be applied simultaneously.
SEIKO NPC CORPORATION —3
SM6801A
Electrical Characteristics
DC Characteristics
Standard voltage
VSS1 = VSS2 = 0V, VDD1 = VDD2 = 2.7 to 3.6V, VDD3 = VDD4 = 2.7 to 5.5V, Ta = −40 to 85°C unless otherwise noted.
Rating Parameter Pin Symbol IDD1A IDD1S Current consumption VDD2 VDD3 = VDD4 = 3.6V IDDAS VIH1 VIL1 Input voltage 2 Input current 1 Input current 2 MUTEN, PDWN TESTN, DRCN, MUTEN, PDWN VIH2 VIL2 IIL1 ILH1 (Note 2) VDD3 = VDD4 = 5V HIGH level LOW level HIGH level LOW level VIN = VSS VIN = VDDS – 0.7VDD1 – 1.6 – − − 0.1 – – – – – − 0.3 – 0.3VDD1 – 0.4 90 1.0 µA V V V V µA µA – 0.1 0.3 µA IDDAA (Note 1) (Note 2) VDD3 = VDD4 = 3.6V (Note 1) VDD3 = VDD4 = 5V – 1.0 6.0 mA Conditions min – – – VDD1 typ 3.8 0.1 0.3 max 6.0 0.5 1.5 mA µA mA Unit
Input voltage 1
TESTN, DRCN
Note 1. MUTEN = HIGH, PDWN = HIGH, input and VREF1 connected by 600Ω, DRCN = HIGH, no-load output Note 2. MUTEN = LOW, PDWN = LOW, input and VREF1 connected by 600Ω, DRCN = HIGH, no-load output
Low voltage
VSS1 = VSS2 = 0V, VDD1 = VDD2 = VDD3 = VDD4 = 2.0 to 3.2V, Ta = −40 to 85°C unless otherwise noted.
Rating Parameter Pin Symbol IDD1A IDD1S VDD2 IDDAA IDDAS Input voltage 1 TESTN, DRCN VIH1 VIL1 Input voltage 2 Input current 1 Input current 2 MUTEN, PDWN TESTN, DRCN, MUTEN, PDWN VIH2 VIL2 IIL1 ILH1 (Note 1) (Note 2) (Note 1) (Note 2) HIGH level LOW level HIGH level LOW level VIN = VSS VIN = VDDS Conditions min – – – – 0.7VDD1 – 1.6 – − − VDD1 Current consumption typ 1.6 0.1 0.2 0.1 – – – – – − max 6.0 0.5 1.5 0.3 – 0.3VDD1 – 0.4 90 1.0 mA µA mA µA V V V V µA µA Unit
Note 1. MUTEN = HIGH, PDWN = HIGH, input and VREF1 connected by 600Ω, DRCN = HIGH, no-load output Note 2. MUTEN = LOW, PDWN = LOW, input and VREF1 connected by 600Ω, DRCN = HIGH, no-load output Note. The usage with direct coupling to load is recommended for operating VDD1, VDD2, VDD3 and VDD4 at ≤ 2.4V. When using LC-type LPF, the ringing phenomena due to rush current may be judged as short-circuit of the load. In this case, the normal operation will start after the mute for 5 seconds.
SEIKO NPC CORPORATION —4
SM6801A AC Analog Characteristics VDD1 = VDD2 = VDD3 = VDD4 = 3.6V, VSS1 = VSS2 = 0V, 0.708Vrms analog input amplitude, 1kHz input signal frequency, Ta = 25°C, "Measurement Block Diagram", "Measurement Conditions", "Measurement Circuit", DRCN = PDWN = MUTEN = HIGH, unless otherwise noted.
Analog Input Characteristics (IN)
Standard voltage: VDD1 = VDD2 = VDD3 = VDD4 = 3.6V, VSS1 = VSS2 = 0V
Rating Parameter Reference input amplitude 1 Reference input amplitude 2 Input resistance Input clipping voltage Symbol VAI1 VAI2 RIN VCLP PO = 0.5W PO = 0.25W PO = 0.05W Conditions min – – 40 0.7 typ 0.708 0.178 60 1 max – – 80 1.3 Vrms Vrms kΩ Vrms Unit
Low voltage: VDD1 = VDD2 = VDD3 = VDD4 = 2.4V, VSS1 = VSS2 = 0V
Rating Parameter Reference input amplitude 1 Reference input amplitude 2 Input resistance Input clipping voltage Symbol VAI1 VAI2 RIN VCLP PO = 100mW PO = 42mW PO = 8mW Conditions min – – 40 0.38 typ 0.316 0.045 60 0.48 max – – 80 0.58 Vrms Vrms kΩ Vrms Unit
SEIKO NPC CORPORATION —5
SM6801A
Analog Output Characteristics (OUTP, OUTN)
Standard voltage: VDD1 = VDD2 = VDD3 = VDD4 = 3.6V, VSS1 = VSS2 = 0V
Rating Parameter Symbol Conditions min Voltage gain 1 Voltage gain 2 Residual noise voltage Total harmonic distortion + noise Maximum output power Mute-mode output voltage HIGH-level output voltage LOW-level output voltage Efficiency Ripple rejection ratio 1 A1 A2 VNS THD + N POMAX VMUTE VOH VOL EEF PSRR1 Maximum output power conditions (Note 1) DRCN = HIGH, input amplitude = 0.1Vrms DRCN = LOW, input amplitude = 0.05Vrms DRCN = HIGH, input and VREF1 connected by 600Ω PO = 0.25W, reference input amplitude 1 Output power when THD = 10% Output power when MUTEN = LOW 4.0 13.0 – – 0.6 –90.0 VDDP – 0.2 0 80 – typ 6.0 15.0 78 0.4 0.7 –110 VDDP – 0.02 0.02 83 –60 max 8.0 17.0 120 1.0 0.8 – VDDP + 0.2 0.2 – – dB dB µVrms % W dBV V V % dB Unit
Note 1. DRCN = HIGH, 217Hz ripple frequency, 0.2Vrms ripple amplitude on VDD1/VDD2/VDD3/VDD4, input and VREF1 connected by 600Ω.
Low voltage: VDD1 = VDD2 = VDD3 = VDD4 = 2.4V, VSS1 = VSS2 = 0V
Rating Parameter Symbol Conditions min Voltage gain 1 Voltage gain 2 Residual noise voltage Total harmonic distortion + noise Maximum output power Mute-mode output voltage HIGH-level output voltage LOW-level output voltage A1 A2 VNS THD + N POMAX VMUTE VOH VOL DRCN = HIGH, input amplitude = 0.1Vrms DRCN = LOW, input amplitude = 0.05Vrms DRCN = HIGH, input and VREF1 connected by 600Ω PO = 42mW, reference input amplitude V = 316.2mVrms Output power when THD = 10% Output power when MUTEN = LOW – – – – – – – – typ 5.6 14.5 120 0.8 0.280 –110 VDDP – 0.02 0.02 max – – – – – – – – dB dB µVrms % W dBV V V Unit
SEIKO NPC CORPORATION —6
SM6801A
Reference Voltage Characteristics (VREF1)
Rating Parameter Reference output voltage 1 Symbol min VREF1 0.45VDDS typ 0.5VDDS max 0.55VDDS V Unit
Measurement Block Diagram
40µH SPOUT POS 1µF
BALANCED INPUT +
EVALUATION BOARD
40µH SPOUT NEG 1µF
8Ω
AUDIO ANALYZER
BALANCED INPUT −
Measurement Conditions
Parameter Audio Analyzer (Audio Precision System Two Cascade) Built-in Filters Low-pass filter (20kHz) ON High-pass filter (22Hz) ON Low-pass filter (20kHz) ON High-pass filter (22Hz) ON A-weighted
Excluding residual noise
Residual noise voltage
SEIKO NPC CORPORATION —7
SM6801A
Measurement Circuit
DRCN MUTEN VDD2 PDWN SW2* SW3* SW4*
H L
H L
H L
POWER VDD MUTEN PDWN VDD2 VDD4
C6 R5* OUTP VSS2 R6* OUTN C7
1µ SPOUT POS POWER VSS (0V) SPOUT NEG 1µ
DRCN VDD1 C1 1µ C5 1µ VDD1 VREF1
SIGNAL INPUT
C4
150p
TESTN
IN
IN VSS1 EQN EQP
VDD3
SW1* H L
ANALOG VSS (0V)
EQP EQN VSS1
TESTN
SIGNAL VSS (0V)
Note. *C2, C3: not inserted *R1, R2, R3, R4: not inserted *R5, R6: series resistors for dielectric speaker *SW1: HIGH = Normal, LOW = Test *SW2: LOW = DRC on, HIGH = DRC off *SW3: LOW = Mute on, HIGH = Mute off *SW4: LOW = Power off, HIGH = Power on
SEIKO NPC CORPORATION —8
SM6801A
FUNCTIONAL DESCRIPTION
Power-down (PDWN)
The device enters power-down mode when PDWN goes LOW. When powered-down, the outputs become high impedance and the internal oscillation stops. In power-down mode, the MUTEN pin should be held LOW.
Mute (MUTEN)
Mute operation occurs when MUTEN goes LOW. In mute mode, the outputs become high impedance. During mute operation, the protection circuit operation is disabled, but the outputs are protected against output short circuits by their high impedance state. When power is applied, MUTEN should be held LOW for a short interval, shown in the timing diagram below, to prevent pop noise from the speaker. Also, applying and releasing mute operation after power is applied can occur at high speed without generating pop noise.
min. 40msec
PDWN MUTEN
Note. VREF1 load capacitance = 1µF
Protection Circuit
The protection circuit operates if there is an output short-circuit to the supply, short-circuit to ground, or other excessive load abnormal condition lasting longer than approximately 1µs. Normal operation resumes after approximately 5 seconds. When the protection circuit becomes active, the outputs become high impedance. The usage with direct coupling to load is recommended for operating VDD1, VDD2, VDD3 and VDD4 at ≤ 2.4V. When using LC-type LPF, the ringing phenomena due to rush current may be judged as short-circuit of the load. In this case, the normal operation will start after the mute for 5 seconds.
SEIKO NPC CORPORATION —9
SM6801A
Input Equalizer (IN, EQP, EQN)
An input equalizer network can be connected to pins IN, EQP and EQN, as shown in the input equivalent circuit and equalizer circuit below.
R01 R02 C02
R04 R03 C03 C04
EQP 5
EQN 6 60k
IN'
C01
60k 4 IN VREF1
− +
The frequency response of the equalizer circuit is given by the following equation, where ƒ is the frequency.
1 1 + 60000 Response = 20 × log10 1 + 2πƒC01 1 1 R03 + 2πƒC03 + 1 + 2πƒC04 R04 [dB] 1 1 1 + + 60000 R01 1 R02 + 1 2πƒC02
Dynamic Range Compression Mode (DRCN)
The dynamic range compression mode is set when DRCN is LOW. When a compression mode is used, the gain for small input signals is increased while large input signals are converted using a curve that performs soft-clipping. This increases the average sound pressure level emitted from the speaker during playback.
-40 -35 -30 -25 -20 -15 -10
-5
0
5
10 10 5
DRC mode Output [dBV]
0 -5 -10 -15 -20
normal mode
-25 -30 -35 -40
Input [dBV]
SEIKO NPC CORPORATION —10
SM6801A
TYPICAL APPLICATION CIRCUITS
Dynamic Speaker
LC-type LPF Connection
47µF OUTPUT IN SPOUT POS 1µF
SOUND GENERATOR IC
SM6801
47µF SPOUT NEG 1µF
Direct Connection
OUTPUT
IN
SPOUT POS
SOUND GENERATOR IC
SM6801
SPOUT NEG
Dielectric Speaker
A dielectric speaker is capacitive in nature, and therefore requires output resistor connection.
OUTPUT
IN
SPOUT POS
4Ω
SOUND GENERATOR IC
*
SM6801
4Ω
SPOUT NEG
* Dielectric speaker Taiyo Yuden MLS20070, MLS23070, MLS25070 or similar
SEIKO NPC CORPORATION —11
SM6801A
Mounting Circuits
Connection to LC Filter
VDD3
VCC
Ferrite beads
VDD2
1µF 1µF
Ferrite beads
VSS2 VDD4
+
VCC
VDD1 1µF VSS1
SM6801
OUTP OUTN
Ferrite beads Ferrite beads
Z0
VSS
+
LC filter Speaker LC filter
Direct Connection to Load
VDD3
VCC
Ferrite beads
VDD2
10µF 10µF
Ferrite beads
VSS2 VDD4
+
VCC
VDD1 1µF VSS1
SM6801
OUTP OUTN
Ferrite beads
Z0
VSS
+
Speaker
Ferrite beads
Note. As for the wiring to VDD1, VDD2, VDD3, VDD4, VSS1, and VSS2, we recommend to wire from the power supply block. The recommended value of internal impedance (Z0) is approximately less than 1/40 of load resistance.
SEIKO NPC CORPORATION —12
SM6801A
TYPICAL CHARACTERISTICS
Measurement conditions: Refer to “Analog Output Characteristics”. Measurement circuit: Refer to “Measurement Circuit”.
+10 +5.833 +1.667 -2.5 -6.667
DRC
Output [dBV]
-10.833 -15
NORMAL
-19.167 -23.333 -27.5 -31.667 -35.833 -40 -40
-35
-30
-25
-20
-15
-10
-5
+0
+5
Input [dBV]
Input vs. Output
1.8 1.5 Output power [W] 1.2 0.9 0.6 0.3 0 2.5 3 3.5 4 Supply voltage [V] 4.5 5 5.5
Supply voltage vs. Output power
100 50 20 10
10 5 2
THD + N [%]
5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 -25 -22.5
THD + N
500m 200m 100m 50m 20m 10m 5m 2m 1m
-20
-17.5
-15
-12.5
-10
-7.5
-5
-2.5
+0
+2.5
+5
Input [dBV]
Input vs. THD + N and output power
SEIKO NPC CORPORATION —13
Output power [W]
Output power
1
SM6801A
10 5
VDD3 = VDD4 = 5.5V
2 1 500m
VDD3 = VDD4 = 5V
Output power [W]
200m 100m 50m
20m 10m 5m
VDD3 = VDD4 = 4.5V
2m 1m -25 -22.5 -20 -17.5 -15 -12.5 -10 -7.5 -5 -2.5 +0
Input [dBV]
Input power vs. Output power
-70 -75 -80 -85 -90 -95
Noise [dB]
-100 -105 -110 -115 -120 -125 -130 -135 -140 20 50 100 200 500 1k 2k 5k 10k 20k
Frequency [Hz]
Residual noise vs. Frequency
10 5 2 1 +6 +5
THD + N
+4 +3 +2 +1 -0 -1 -2
THD + N [%]
0.2 0.1 0.05 0.02 0.01 0.005 0.002 0.001 20 50 100 200 500 1k 2k 5k 10k 20k
Output
-3 -4 -5 -6
Frequency [Hz]
THD + N and output voltage vs. Frequency
+0 -10 -20 -30
PSRR [dBr]
-40 -50 -60 -70 -80 -90 -100 10
PSRR
20
50
100
200
500
1k
2k
5k
10k
20k
Frequency [Hz]
PSRR vs. Frequency
SEIKO NPC CORPORATION —14
Output [dBr]
0.5
SM6801A
FOOTPRINT PATTERN
3.6 ± 0.1 2.2 ± 0.1 0.5 × 3 = 1.5 ± 0.05
0.
32
0.5 × 3 = 1.5 ± 0.05
3.6 ± 0.1
2.2 ± 0.1
0.25 ± 0.05
0.7 ± 0.1
SEIKO NPC CORPORATION —15
SM6801A
Please pay your attention to the following points at time of using the products shown in this document. The products shown in this document (hereinafter “Products”) are not intended to be used for the apparatus that exerts harmful influence on human lives due to the defects, failure or malfunction of the Products. Customers are requested to obtain prior written agreement for such use from SEIKO NPC CORPORATION (hereinafter “NPC”). Customers shall be solely responsible for, and indemnify and hold NPC free and harmless from, any and all claims, damages, losses, expenses or lawsuits, due to such use without such agreement. NPC reserves the right to change the specifications of the Products in order to improve the characteristic or reliability thereof. NPC makes no claim or warranty that the contents described in this document dose not infringe any intellectual property right or other similar right owned by third parties. Therefore, NPC shall not be responsible for such problems, even if the use is in accordance with the descriptions provided in this document. Any descriptions including applications, circuits, and the parameters of the Products in this document are for reference to use the Products, and shall not be guaranteed free from defect, inapplicability to the design for the mass-production products without further testing or modification. Customers are requested not to export or re-export, directly or indirectly, the Products to any country or any entity not in compliance with or in violation of the national export administration laws, treaties, orders and regulations. Customers are requested appropriately take steps to obtain required permissions or approvals from appropriate government agencies.
SEIKO NPC CORPORATION
15-6, Nihombashi-kabutocho, Chuo-ku, Tokyo 103-0026, Japan Telephone: +81-3-6667-6601 Facsimile: +81-3-6667-6611 http://www.npc.co.jp/ Email: sales@npc.co.jp
NC0416DE 2007.06
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