SM6800A Class-D Mono Amplifier for Mobile Telephones OVERVIEW The SM6800A is an analog-input, class-D mono amplifier. Class-D operation provides high efficiency and low power consumption. The device also incorporates a selectable 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 20-pin QFN packages, and requires only a peripheral chip capacitor to form a miniature amplifier circuit. ■ ■ ■ ■ ■ Operating supply voltage: 2.7 to 4.3V Low current consumption: 4.8mA (VDD = 3.6V) Output power: 0.7W (VDD = 3.6V, 8Ω load) Output fundamental frequency: 125kHz Gain • 4.5dB (Normal) • 12dB to 4.5dB automatic adjustment in response to the input level (Dynamic range compression mode) Silicon-gate CMOS process Package: 20-pin QFN (Top view) PROT TEST TM2 TM1 VSS3 ■ ■ PINOUT 20 19 18 17 16 VDD1 IN EQP EQN VSS1 15 14 13 12 11 1 2 3 4 5 6 7 8 9 10 APPLICATIONS ■ ■ ■ Cellular phone PDA Digital still camera VDD3 OUTP VSS2 OUTN VDD2 VREF3 VREF2 VREF1 PDWN MUTEN FEATURES PACKAGE DIMENSIONS (Unit: mm) ORDERING INFORMATION 4.20 ± 0.20 1 0.50 0.05 M 1.00MAX 0.05 0.22 ± 0.05 0.22 0.60 ± 0.10 + 0.03 0.02 − 0.02 20-pin QFN 4.00 ± 0.10 SM6800AB 20 Package 4.20 ± 0.20 4.00 ± 0.10 Device NIPPON PRECISION CIRCUITS INC.—1 SM6800A BLOCK DIAGRAM EQP EQN VDD1 VSS1 TM1 TM2 TEST VSS3 VDD2 IN VSS2 − + LEVEL SHIFTER BUFFER OUTP LEVEL SHIFTER BUFFER OUTN PWM Modulator VREF1 VREF2 − + VREF1 VREF2 VREF3 BIAS, VREF1, VREF2, VREF3 OSC VREF1 VREF2 VREF3 MUTE, POWERDOWN, PROTECTION VDD3 MUTEN PDWN PIN DESCRIPTION Number Name1 I/O2 1 VDD1 – Supply (input system) 2 IN I Signal input 3 EQP I Equalizer network connection 4 EQN I Equalizer network connection 5 VSS1 – Ground (input system) 6 VREF3 – Reference voltage 3 (internal bias voltage monitor. No connection for normal operation) 7 VREF2 – Reference voltage 2 (internal bias voltage monitor. No connection for normal operation) 8 VREF1 – Reference voltage 1 (bias voltage) 9 PDWN I Power-down control (active LOW) 10 MUTEN I Mute control (active LOW) 11 VDD2 – Supply (OUTN stage) 12 OUTN O Speaker minus (–) output 13 VSS2 – Ground (OUTP and OUTN stages) 14 OUTP O Speaker plus (+) output 15 VDD3 – Supply (OUTP stage) 16 VSS3 – Ground (output system) 17 TM1 I Dynamic range compression mode setting 1 18 TM2 I Dynamic range compression mode setting 2 19 TEST Ip Test pin (HIGH: normal operation, LOW: test mode) 20 PROT O Protection circuit output (HIGH: protection circuit operation, LOW: normal operation) Function 1. VDDS = VDD1, VDDP = VDD2 = VDD3, VSS = VSS1 = VSS2 = VSS3 2. Ip = input pin with built-in pull-up resistor NIPPON PRECISION CIRCUITS INC.—2 SM6800A SPECIFICATIONS Absolute Maximum Ratings Parameter Symbol Rating Unit Supply voltage range VDDS, VDDP −0.3 to 4.6 V Supply voltage ground VSS 0 V Input voltage range VIN VSS − 0.3 to VDDS + 0.3 V TSTG −55 to +125 °C Output current IO 300 mA Power dissipation1 PD 340 mW Storage temperature range 1. Under NPC measurement conditions, θJa = 116.2°C/W. The power dissipation is given by: PD = ((TJMAX − Ta)/ θJa) where TJMAX = 125°C and Ta = 85°C Recommended Operating Conditions VSS = VSS1 = VSS2 = VSS3 = 0V, VDDS =VDD1, VDDP = VDD2 = VDD3 unless otherwise noted Parameter Symbol Rating Unit Supply voltage 1 VDDS 2.7 to 4.3 V Supply voltage 2 VDDP 2.7 to 4.3 V VDD3 − VDD2 ± 0.1 V Ta −40 to 85 °C Supply voltage difference Operating temperature range Electrical Characteristics DC Characteristics VSS1 = VSS2 = VSS3 = 0V, VDD1 = 2.7 to 4.3V, VDD2 = VDD3 = 2.7 to 4.3V, Ta = −40 to 85°C unless otherwise noted Rating Parameter Pin VDD1 Current consumption VDD2 + VDD3 Symbol Conditions Unit min typ max IDD1A (Note 1) – 4.6 8.0 mA IDD1S (Note 2) – 0.2 0.5 µA IDDAA (Note 1) – 0.2 0.6 mA IDDAS (Note 2) – 0.1 0.3 µA Input voltage 1 TEST VIH1 HIGH level 0.8VDDS – – V TM1, TM2, MUTEN, PDWN VIH2 HIGH level 0.9VDDS – – V Input voltage 2 VIL2 LOW level – – 0.4 V Input leakage current 1 TEST ILH1 VIN = VDD1 − – 1.0 µA TM1, TM2, MUTEN, PDWN ILH2 VIN = VDD1 − – 1.0 µA Input leakage current 2 ILL2 VIN = 0V − − 1.0 µA Note 1: MUTEN = HIGH, PDWN = HIGH, input and VREF1 connected by 600Ω, TM1 = TM2 = LOW, no-load output Note 2: MUTEN = LOW, PDWN = LOW, input and VREF1 connected by 600Ω, TM1 = TM2 = LOW, no-load output NIPPON PRECISION CIRCUITS INC.—3 SM6800A AC Analog Characteristics VDD1 = VDD2 = VDD3 = 3.6V, VSS1 = VSS2 = VSS3 = 0V, 0.708Vrms analog input amplitude, 1kHz input signal frequency, Ta = 25°C, "Measurement block diagram”, "Measurement conditions”, "Measurement circuit”, TM1 = TM2 = LOW, PDWN = MUTEN = HIGH, unless otherwise noted Analog input characteristics (IN) Rating Parameter Symbol Conditions Unit min typ max Reference input amplitude 1 VAI1 PO = 0.2W – 0.708 – Vrms Reference input amplitude 2 VAI2 PO = 0.05W – 0.178 – Vrms Input resistance RIN 48 60 72 kΩ Input clipping voltage VCLP 0.7 1 1.3 Vrms = 0.5W PO Analog output characteristics (OUTP, OUTN) Rating Parameter Symbol Conditions Unit min typ max Voltage gain 1 A1 TM1 = TM2 = LOW, reference input amplitude 1 2.5 4.5 6.5 dB Voltage gain 2 A2 TM1 = HIGH, TM2 = LOW, reference input amplitude 2 10.0 12.0 14.0 dB Residual noise voltage VNS TM1 = TM2 = LOW, input and VREF1 connected by 600Ω – 68 90 µVrms THD + N PO = 0.2W, reference input amplitude 1 – 0.4 1.0 % 0.6 0.7 0.8 W – 90.0 – 110 – dBV Total harmonic distortion + noise Maximum output power POMAX Output power when THD = 10% Mute-mode output voltage VMUTE Output power when MUTEN = LOW HIGH-level output voltage VOH VDDP – 0.1 VDDP – 0.02 VDDP V LOW-level output voltage VOL 0 0.02 0.1 V Efficiency EEF 80 83 – % Maximum output power conditions Reference voltage characteristics (VREF1) Rating Parameter Reference output voltage 1 Symbol VREF1 Unit min typ max 0.45VDDS 0.5VDDS 0.55VDDS V NIPPON PRECISION CIRCUITS INC.—4 SM6800A Measurement block diagram 40µH BALANCED INPUT + SPOUT POS 1µF EVALUATION BOARD 8Ω AUDIO ANALYZER 40µH BALANCED INPUT − SPOUT NEG 1µF Measurement conditions Parameter Audio Analyzer (Audio Precision System Two Cascade) Built-in Filters Excluding residual noise Low-pass filter (20kHz) ON High-pass filter (22Hz) ON Residual noise voltage Low-pass filter (20kHz) ON High-pass filter (22Hz) ON A-weighted NIPPON PRECISION CIRCUITS INC.—5 SM6800A Measurement circuit SW3 L C1 POWER VDD (2.7 to 4.3V) VDD1 1µ EQP TM1 L TM2 L TEST H SIGNAL VDD (2.7 to 4.3V) VDD3 IN OUTP POWER VDD R7* C8 1µ SPOUT POS 0 (JUMPER) C3 150p R8* 0 (JUMPER) MUTEN VSS1 PDWN POWER VDD (2.7 to 4.3V) VREF1 VSS1 SIGNAL VSS (0V) SPOUT NEG OUTN EQN EQN POWER VSS (0V) VSS2 EQP C4 1µ VREF2 SIGNAL INPUT H PROT IN TM1 SW5 H VREF3 VDD1 TM2 SW4 VSS3 TEST PROT (H NORMAL) C9 1µ VDD2 C5 1µ SW1* SW2* H H L L ANALOG VSS (0V) Note. *C2, C6, C7: not inserted *R1, R2, R3: not inserted *R7, R8: series resistors for dielectric speaker *SW1: HIGH = Power on, LOW = Power off *SW2: LOW = Mute on, HIGH = Mute off D-Range CP MODE TM1 TM2 OFF L L 1 H L 2 L H 3 H H NIPPON PRECISION CIRCUITS INC.—6 SM6800A 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 PROT output goes HIGH and the outputs become high impedance. NIPPON PRECISION CIRCUITS INC.—7 SM6800A 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 R04 R02 C02 R03 C03 C04 EQP 3 EQN 4 60k 60k C01 2 − IN + 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 R03 + 1 2πƒC03 + 1 + 2πƒC04 R04 [dB] 1 1 1 + + 60000 R01 1 R02 + 1 2πƒC02 Dynamic Range Compression Mode (TM1, TM2) The dynamic range compression mode is selected by the state of the TM1 and TM2 inputs. 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. Dynamic range compression mode TM1 TM2 Effect OFF L L No effect 1 H L Small effect 2 L H Medium effect 3 H H Large effect NIPPON PRECISION CIRCUITS INC.—8 SM6800A TYPICAL APPLICATION CIRCUITS Dynamic Speaker LC-type LPF connection 47µF OUTPUT 2 SPOUT POS 14 1µF SOUND GENERATOR IC SM6800 47µF SPOUT NEG 12 1µF Direct connection OUTPUT 2 SOUND GENERATOR IC SPOUT POS 14 SM6800 SPOUT NEG 12 Dielectric Speaker A dielectric speaker is capacitive in nature, and therefore requires output resistor connection. OUTPUT SOUND GENERATOR IC 2 4Ω SPOUT POS 14 * SM6800 4Ω SPOUT NEG 12 * Dielectric speaker Taiyo Yuden MLS20070, MLS23070, MLS25070 or similar NIPPON PRECISION CIRCUITS INC.—9 SM6800A TYPICAL CHARACTERISTICS Measurement conditions: Refer to “Analog output characteristics”. Measurement circuit: Refer to “Measurement circuit”. 100 10 50 5 20 2 10 1 Output power 200m 100m 1 0.5 50m 0.2 20m 0.1 10m 0.05 5m 0.02 2m 0.01 -25 1m -22.5 -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 (VDD = 3.6V) +10 +7.5 D-RANGE-CP3 D-RANGE-CP2 +5 +2.5 Output [dBV] THD + N [%] THD + N 2 Output power [W] 500m 5 +0 -2.5 -5 Normal mode -7.5 D-RANGE-CP1 -10 -12.5 -15 -17.5 -20 -20 -18 -16 -14 -12 -10 -8 -6 -4 -2 -0 +2 +4 Input [dBV] Input vs. Output (VDD = 3.6V) NIPPON PRECISION CIRCUITS INC.—10 SM6800A -70 -75 -80 Residual noise [dBV] -85 -90 -95 -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 (VDD = 3.6V) +6 +5 +4 THD + N 2 1 0.5 +3 +2 0.2 0.1 0.05 +1 0.02 0.01 0.005 -2 -3 -0 -1 Output voltage -4 -5 0.002 0.001 Output voltage [dBr] THD + N [%] 10 5 -6 20 50 100 200 500 1k 2k 5k 10k 20k Frequency [Hz] THD + N and Output voltage vs. Frequency (VDD = 3.6V) NIPPON PRECISION CIRCUITS INC.—11 SM6800A 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 NIPPON PRECISION CIRCUITS INC. (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. NIPPON PRECISION CIRCUITS INC. 4-3, Fukuzumi 2-chome, Koto-ku, Tokyo 135-8430, Japan Telephone: +81-3-3642-6661 Facsimile: +81-3-3642-6698 http://www.npc.co.jp/ Email: [email protected] NC0316AE 2004.09 NIPPON PRECISION CIRCUITS INC.—12