ANALOG DEVICES ssm2319 Service Manual

Filterless, High Efficiency,

S

FEATURES

Filterless Class-D amplifier with ultraefficient spread-

spectrum Σ-Δ modulation
Internal modulator synchronization (SYNC)
3 W into 3 Ω load and 1.4 W into 8 Ω load at 5.0 V supply

with <1% total harmonic distortion (THD)
90% efficiency at 5.0 V, 1.4 W into 8 Ω speaker
Signal-to-noise ratio (SNR): 98 dB
Single-supply operation: 2.5 V to 5.5 V
Ultralow shutdown current: 20 nA
Short-circuit and thermal protection with autorecovery
Available in 9-ball, 1.5 mm × 1.5 mm WLCSP
Pop-and-click suppression
Built-in resistors reduce board component count
Default fixed 12 dB or user-adjustable gain setting

APPLICATIONS

Mobile phones
MP3 players
Portable gaming
Portable electronics
Educational toys

GENERAL DESCRIPTION

The SSM2319 is a fully integrated, high efficiency Class-D
audio amplifier. It is designed to maximize performance for
mobile phone applications. The application circuit requires a
minimum of external components and operates from a single

2.5 V to 5.5 V supply. It is capable of delivering 3 W of continuous
output power with <1% THD + N driving a 3 Ω load from a

5.0 V supply.

Mono 3 W Class-D Audio Amplifier

SSM2319

The SSM2319 features a high efficiency, low noise modulation
scheme that does not require any external LC output filters. The
modulation continues to provide high efficiency even at low output
power. It operates with 90% efficiency at 1.4 W into 8 Ω or 85%
efficiency at 3 W into 3 Ω from a 5.0 V supply and has an SNR
of 98 dB. Spread-spectrum pulse density modulation is used to
provide lower EMI-radiated emissions compared with other
Class-D architectures.

SYNC can be activated in the event that end users are concerned
about clock intermodulation (beating effect) of several amplifiers in
close proximity.

The SSM2319 has a micropower shutdown mode with a typical
shutdown current of 20 nA. Shutdown is enabled by applying a
logic low to the

The device also includes pop-and-click suppression circuitry.
This minimizes voltage glitches at the output during turn-on and
turn-off, reducing audible noise on activation and deactivation.

The default gain of the SSM2319 is 12 dB, but users can reduce
the gain by using a pair of external resistors (see the Gain section).

The SSM2319 is specified over the industrial temperature range
of −40°C to +85°C. It has built-in thermal shutdown and output
short-circuit protection. It is available in a 9-ball, 1.5 mm × 1.5 mm
wafer level chip scale package (WLCSP).

SD

pin.

FUNCTIONAL BLOCK DIAGRAM

10µF

SSM2319

AUDIO IN–

AUDIO IN+

HUTDOWN

*INPUT CAPACITORS ARE O PTIONAL IF INPUT DC COMMON-MO DE

VOLTAGE IS APPROXIMATELY V

Rev. 0

Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.

0.1µF*

0.1µF*

IN–

IN+

SD

40kΩ

40kΩ

DD

MODULATOR

BIAS

/2.

160kΩ

(Σ-Δ)

160kΩ

0.1µF

VDD

FET

DRIVER

POP/CLICK

INTERNAL

OSCILLATOR

Figure 1.

SUPPRESSION

GND

SYNCI

SYNC INPUT

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] ©2008 Analog Devices, Inc. All rights reserved.

SYNC

VBATT

2.5V TO 5.5V

OUT+

OUT–

SYNCO

SYNC OUTPUT

07550-001

SSM2319

TABLE OF CONTENTS

Features .............................................................................................. 1

Applications ....................................................................................... 1

General Description ......................................................................... 1

Functional Block Diagram .............................................................. 1

Revision History ............................................................................... 2

Specifications ..................................................................................... 3

Absolute Maximum Ratings ............................................................ 5

Thermal Resistance ...................................................................... 5

ESD Caution .................................................................................. 5

Pin Configuration and Function Descriptions ............................. 6

Typical Performance Characteristics ............................................. 7

Typical Application Circuits .......................................................... 12

REVISION HISTORY

8/08—Revision 0: Initial Version

Theory of Operation ...................................................................... 14

Overview ..................................................................................... 14

Gain .............................................................................................. 14

Pop-and-Click Suppression ...................................................... 14

Output Modulation Description .............................................. 14

Layout .......................................................................................... 15

Input Capacitor Selection .......................................................... 15

Power Supply Decoupling ......................................................... 15

Syncronization (SYNC) Operation .......................................... 15

Outline Dimensions ....................................................................... 17

Ordering Guide .......................................................................... 17

Rev. 0 | Page 2 of 20

SSM2319

SPECIFICATIONS

VDD = 5.0 V, TA = 25oC, RL = 8 Ω +33 μH, SYNCI = GND (standalone mode), unless otherwise noted.

Table 1.

Parameter Symbol Conditions Min Typ Max Unit

DEVICE CHARACTERISTICS

Output Power P

OUT

R

R

R

R

R

R

R

R

R

R

R

R

R

R

R

R

R

Efficiency η P

Total Harmonic Distortion + Noise THD + N P

P

Input Common-Mode Voltage Range VCM 1.0 VDD − 1 V

Common-Mode Rejection Ratio CMRR

Average Switching Frequency fSW 300 kHz

Differential Output Offset Voltage V

OOS

POWER SUPPLY

Supply Voltage Range V

DD

Power Supply Rejection Ratio PSRR VDD = 2.5 V to 5.0 V, dc input floating/ground 70 85 dB

PSRR

Supply Current I

SY

V

V

V

V

V

Shutdown Current ISD

GAIN CONTROL

Closed-Loop Gain Av 12 dB

Differential Input Impedance Z

IN

SHUTDOWN CONTROL

Input Voltage High V

Input Voltage Low V

Turn-On Time t

Turn-Off Time t

Output Impedance Z

IH

IL

WU

SD

OUT

RL = 8 Ω, THD = 1%, f = 1 kHz, 20 kHz BW, VDD = 5.0 V 1.41 W

= 8 Ω, THD = 1%, f = 1 kHz, 20 kHz BW, VDD = 3.6 V 0.72 W

L

= 8 Ω, THD = 1%, f = 1 kHz, 20 kHz BW, VDD = 2.5 V 0.33 W

L

= 8 Ω, THD = 10%, f = 1 kHz, 20 kHz BW, VDD = 5.0 V 1.77 W

L

= 8 Ω, THD = 10%, f = 1 kHz, 20 kHz BW, VDD = 3.6 V 0.91 W

L

= 8 Ω, THD = 10%, f = 1 kHz, 20 kHz BW, VDD = 2.5 V 0.42 W

L

= 4 Ω, THD = 1%, f = 1 kHz, 20 kHz BW, VDD = 5.0 V 2.53 W

L

= 4 Ω, THD = 1%, f = 1 kHz, 20 kHz BW, VDD = 3.6 V 1.28 W

L

= 4 Ω, THD = 1%, f = 1 kHz, 20 kHz BW, VDD = 2.5 V 0.56 W

L

= 4 Ω, THD = 10%, f = 1 kHz, 20 kHz BW, VDD = 5.0 V 3.171 W

L

= 4 Ω, THD = 10%, f = 1 kHz, 20 kHz BW, VDD = 3.6 V 1.6 W

L

= 4 Ω, THD = 10%, f = 1 kHz, 20 kHz BW, VDD = 2.5 V 0.72 W

L

= 3 Ω, THD = 1%, f = 1 kHz, 20 kHz BW, VDD = 5.0 V 3.1

L

= 3 Ω, THD = 1%, f = 1 kHz, 20 kHz BW, VDD = 3.6 V 1.52 W

L

= 3 Ω, THD = 1%, f = 1 kHz, 20 kHz BW, VDD = 2.5 V 0.68 W

L

= 3 Ω, THD = 10%, f = 1 kHz, 20 kHz BW, VDD = 5.0 V 3.7

L

= 3 Ω, THD = 10%, f = 1 kHz, 20 kHz BW, VDD = 3.6 V 1.9 W

L

= 3 Ω, THD = 10%, f = 1 kHz, 20 kHz BW, VDD = 2.5 V 0.85 W

L

= 1.4 W, 8 Ω, VDD = 5.0 V 93 %

OUT

= 1 W into 8 Ω, f = 1 kHz, VDD = 5.0 V 0.06 %

OUT

= 0.5 W into 8 Ω, f = 1 kHz, VDD = 3.6 V 0.02 %

OUT

GSM VCM

= 2.5 V ± 100 mV at 217 Hz, output referred 57 dB

1

W

1

W

G = 12 dB 2.0 mV

Guaranteed from PSRR test 2.5 5.5 V

GSM VRIPPLE

= 100 mV at 217 Hz, inputs ac GND, CIN = 0.1 μF 60 dB

VIN = 0 V, no load, VDD = 5.0 V 3.6 mA

= 0 V, no load, VDD = 3.6 V 3.2 mA

IN

= 0 V, no load, VDD = 2.5 V 2.7 mA

IN

= 0 V, load = 8 Ω + 33 μH, VDD = 5.0 V 3.7 mA

IN

= 0 V, load = 8 Ω + 33 μH, VDD = 3.6 V 3.3 mA

IN

= 0 V, load = 8 Ω + 33 μH, VDD = 2.5 V 2.8 mA

IN

= GND

SD

SD = VDD

20 nA

40 kΩ

ISY ≥ 1 mA 1.2 V
ISY ≤ 300 nA 0.5 V
SD rising edge from GND to VDD

SD falling edge from VDD to GND

= GND

SD

28 ms
5 μs
>100 kΩ

Rev. 0 | Page 3 of 20

SSM2319

Parameter Symbol Conditions Min Typ Max Unit

NOISE PERFORMANCE

Output Voltage Noise en

Signal-to-Noise Ratio SNR P

= 3.6 V, f = 20 Hz to 20 kHz, inputs are ac grounded,

V

DD

= 12 dB, A weighting

A

V

= 1.4 W, RL = 8 Ω 98 dB

OUT

SYNC OPERATIONAL FREQUENCY 5 12 MHz

1

Although the SSM2319 has good audio quality above 3 W, continuous output power beyond 3 W must be avoided due to device packaging limitations.

40 μV

Rev. 0 | Page 4 of 20

SSM2319

ABSOLUTE MAXIMUM RATINGS

Absolute maximum ratings apply at 25°C, unless otherwise noted.

Table 2.

Parameter Rating

Supply Voltage 6 V
Input Voltage V
Common-Mode Input Voltage V
Storage Temperature Range −65°C to +150°C
Operating Temperature Range −40°C to +85°C
Junction Temperature Range −65°C to +165°C
Lead Temperature (Soldering, 60 sec) 300°C
ESD Susceptibility 4 kV

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational section of
this specification is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability.

DD

DD

THERMAL RESISTANCE

θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.

Table 3.

Package Type PCB θJA θJB Unit

9-Ball, 1.5 mm × 1.5 mm WLCSP 1S0P 162 39 °C/W
2S0P 76 21 °C/W

ESD CAUTION

Rev. 0 | Page 5 of 20

SSM2319

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

BALL A1
CORNER

A

B

C

SSM2319

TOP VIEW

BALL SIDE DOW N

(Not to Scale)

Figure 2. Pin Configuration

Table 4. Pin Function Descriptions

Pin No. Mnemonic Description

1A IN− Inverting Input.

1B IN+ Noninverting Input.

1C GND Ground.

SD

2A

Shutdown Input. Active low digital input.

2B SYNCI SYNC Input.

2C VDD Power Supply.

3A SYNCO SYNC Output.

3B OUT− Inverting Output.

3C OUT+ Noninverting Output.

321

07550-002

Rev. 0 | Page 6 of 20