APA4838
Stereo 2.8W Audio Power Amplifier with DC Volume Control and Selectable Gain
Features • • • • • • •
Operating Voltage : 4.5V to 5V Stereo switchable bridged/single-ended power amplifiers DC Volume Control Interface , 0dB to –78dB with precision scale Supply Current , IDD = 15mA at Stereo BTL Low Shutdown Current , IDD = 0.7µA Bridge-Tied Load (BTL) or Single-Ended-(SE) Modes Operation Output Power at 1% THD+N , VDD=5V
General Description
The APA4838 is a monolithic integrated circuit , which provides DC volume control , and a stereo bridged audio power amplifiers capable of producing 2.8W (2.3W) into 3Ω with less than 10% (1.0%) THD+N. APA4838 includes a DC volume control , stereo bridge-tied and single-ended audio power amplifiers , stereo docking outputs , and a selectable gain control , that makes it optimally fittable for notebook PC , multimedia monitors , and other portable applications. The attenuator range of the volume control in APA4838 is from 0dB (DC_Vol=0.8VDD) to –78dB (DC_Vol=0V) with 31 steps. Both of the depop circuitry and the thermal shutdown protection circuitry are integrated in APA4838 , that reduces pops and clicks noise during power up or shutdown mode operation , and protects the chip from being destroyed by over temperature failure. To simplify the audio system design , APA4838 combines a stereo bridgetied loads (BTL) mode for speaker drive and a stereo single-end (SE) mode for headphone drive into a single chip , where both modes are easily switched by the HP Sense input control pin signal. Besides the low supply current design to increase the efficiency of the amplifiers , APA4838 also features a shutdown function which keeps the supply current only 0.7µA (typ).
•
– 2.3W/Ch (typ) into a 3 Ω Load – 2.0W/Ch (typ) into a 4 Ω Load – 1.2W/Ch (typ) into a 8 Ω Load
Output Power at 10% THD+N , VDD=5V
• • • • • •
– 2.8W/Ch (typ) into a 3 Ω Load – 2.3W/Ch (typ) into a 4 Ω Load – 1.5W/Ch (typ) into a 8Ω Load
Single-ended mode at 1.0% THD+N
– 95mW/Ch (typ) into 32Ω Load
Depop Circuitry Integrated Thermal shutdown protection and over current protection circuitry High supply voltage ripple rejection PC99 Compliant 28-pin TSSOP-P (with enhanced thermal pad) power package available
Pin Description
GN D Shutdown G ain Select M ode M ute VDD DC V ol GN D Right Dock Right In 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 Right O ut + V DD Right O ut Right G ain 2 Right G ain 1 GN D BY PA SS HP Sense GN D Left G ain 1 Left G ain 2 Left O ut V DD Left O ut +
Applications • • •
Notebook and Desktop Computers Multimedia Monitors Portable Applications
Beep In Left In Left Dock GN D
ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise customers to obtain the latest version of relevant information to verify before placing orders. Copyright ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 1 www.anpec.com.tw
APA4838
Ordering and Marking Information
APA4838
H a n d lin g C o d e T em p. R an g e P ac ka ge C od e P ackage C ode R : T S S O P -P Tem p. R ange I : -4 0 to 8 5 ° C H a n d lin g C o d e TU : Tube
TR : Tape & R eel
A P A 4838 R :
A P A 4838 XXXXX
X X X X X - D a te C o d e
Block Diagram
Gain Select 20KΩ 20KΩ
Left Gain1
Mode Mute HP Sense DC_Vol Left Dock 20KΩ Left Audio Input 200KΩ 200KΩ Right Audio Input 20KΩ 20KΩ
Mode Control
Left Gain2
20KΩ 10KΩ
0.068µF
10KΩ
- Left Out + Bias + Bias + + Right Out 20KΩ + Power Management 10KΩ 10KΩ 20KΩ Right Gain1 Right Gain2 Click and Pop Suppression Circuitry 20KΩ
2
0.33µF Beep In 0.33µF Right In Right Dock 20KΩ Shutdown VDD GND Beep Detect
Bypass
Copyright ANPEC Electronics Corp. Rev. A.1 - Apr., 2003
+ -
+ Volume Control 31 steps
Left In
20KΩ
20KΩ
+ Left Out
20KΩ - Right Out
0.068µF
20KΩ
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APA4838
Absolute Maximum Ratings
(Over operating free-air temperature range unless otherwise noted.)
Symbol VDD VIN TA TJ TSTG TS VESD PD Parameter Rating Supply Voltage -0.3 to 6 Input Voltage Range, HP sense, Shutdown, -0.3 to VDD+0.3 Mute, Mode, Gain Select Operating Ambient Temperature Range -40 to 85 Maximum Junction Temperature Internally Limited*1 Storage Temperature Range -65 to +150 Soldering Temperature,10 seconds 260 Electrostatic Discharge -2000 to 2000*2 Power Dissipation Internally Limited Unit V V °C °C °C °C V W
Note: 1.APA4838 integrated internal thermal shutdown protection when junction temperature ramp up to 150°C 2.Human body model: C=100pF, R=1500Ω, 3 positives pulse plus 3 negative pulses 3.Machine model: C=200pF, L=0.5µF, 3 positive pulses plus 3 negative pulses
Recommended Operating Conditions
Min. Supply Voltage, VDD High level threshold voltage, VIH Low level threshold voltage, VIL Common mode input voltage, VICM Shutdown, Mute, Mode, Gain Select HP Sense Shutdown, Mute, Mode, Gain Select HP Sense VDD-1.0 4.5 2 4 1.0 3 Max. 5.5 Unit V V V V
Thermal Characteristics
Symbol R THJA Parameter Thermal Resistance from Junction to Ambient in Free Air TSSOP-P* 45 K/W Value Unit
* 5 in2 printed circuit board with 2oz trace and copper pad through 9 25mil diameter vias. The thermal pad on the TSSOP_P package with solder on the printed circuit board.
Copyright ANPEC Electronics Corp. Rev. A.1 - Apr., 2003
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APA4838
Electrical Characteristics
Electrical Characteristics for Entire IC
The following specifications apply for VDD= 5V unless otherwise noted. Limits apply for TA= 25°C
Symbol VDD IDD ISD
Parameter Supply Voltage Quiescent Power Supply Current Shutdown Current
Test Conditions
Min. 4.5
APA4838 Typ. Max. 5.5 15 0.7 25 2.0
Unit V mA µA
VIN=0V, IO=0A VPIN 2= VDD
Electrical Characteristics for Volume Attenuators
The following specifications apply for VDD= 5V. Limits apply for TA= 25°C
Symbol CRANGE AM
Parameter Attenuator Range Mute Attenuation
Test Conditions Gain with VPIN 7=5V Attenuation with VPIN 7=0V VPIN 5=5V, Bridged Mode VPIN 5=5V, Single-Ended Mode
Min.
APA4838 Typ. Max. ±0.5 -65 -78 -70 -70
Unit dB dB
Electrical Characteristics for BTL Mode Operation
The following specifications apply for VDD= 5V unless otherwise noted. Limits apply for TA= 25°C
Symbol VOS PO
Parameter Output Offset Voltage Output Power
Test Conditions
THD+N
PSRR XTALK SNR VN
VIN=0V THD=1%, f=1kHz RL=3Ω RL=4Ω RL=8Ω THD=10%, f=1kHz RL=8Ω Total Harmonic Distortion + Noise AVD=2, f=1kHz RL=4Ω , PO =1.5W RL=8Ω , PO=1W VRIPPLE=100mVRms CB=2.2µF, Power Supply Rejection Ratio RL=8Ω, f=1kHz CB=2.2µF, f=1kHz, RL=8Ω Channel Separation VDD=5V, PO =1.1W, RL=8Ω,A-Wtd Signal-to-Noise Ratio Filter RL=8Ω,A-Wtd Filter Output Noise Voltage
APA4838 Typ. 5 2.3 2.0 1.2 1.5 0.07 0.07 70 90 95 30
Unit mV W
% dB dB dB µV
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APA4838
Electrical Characteristics (Cont.)
Electrical Characteristics for SE Mode Operation (Cont.)
The following specifications apply for VDD= 5V unless otherwise noted. Limits apply for TA= 25°C
Symbol VOS PO THD+N PSRR XTALK SNR VN
Parameter Output Offset Voltage Output Power VIN=0V THD=1%, THD=10%,
Test Conditions f=1kHz, RL=32Ω f=1kHz, RL=32Ω
APA4838 Typ. 5 95 110 0.05 0.07 52 90 102 20
Unit mV mW % % dB dB dB µV
Total Harmonic Distortion AV= 1 , VOUT=1VRMS, RL=10kΩ, f=1kHz plus Noise PO =75mW, RL=32Ω, AV= 1, f=1kHz Power Supply Rejection VRIPPLE=100mVRMS , f=120Hz, CB=2.2µF Ratio Channel Separation CB=2.2µF, RL=8Ω , f=1kHz Signal-to-Noise Ratio PO =75mW, RL=32Ω, A-Wtd Filter Output Noise Voltage RL=32Ω, A-Wtd Filter
Pin Description
Pin Name GND Shutdown Gain Select Mode Mute VDD DC_Vol Right Dock Right In Beep In Left In Left Dock Left Out + Left Out Left Gain 2 Left Gain 1 HP Sense No 1, 8, 14, 20, 23 2 3 4 5 6, 16, 27 7 9 10 11 12 13 15 17 18 19 21 I/O Ground connection for circuitry. I Shutdown mode control signal input, place entire IC in shutdown mode when held high, Idd=0.7uA I Gain select input pin, logic high will switch the amplifier to external gain mode, and logic low will switch to internal unity gain. I Mode select input pin, fixed gain when logic L and gain adjustable mode when logic H. I Mute control input pin, active H. Supply voltage input pin I Volume control function input pin. O Right docking output pin I Right channel audio input pin I Beep signal input pin I Left channel audio input pin O Right docking output pin O Left channel positive output pin O Left channel negative output pin Connect pin 2 of the external gain setting resistor for left channel Connect pin 1 of the external gain setting resistor for left channel I Headphone sense control pin
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Description
Copyright ANPEC Electronics Corp. Rev. A.1 - Apr., 2003
APA4838
Pin Description (Cont.)
Pin Name Bypass Right Gain 1 Right Gain 2 Right Out Right Out + No 22 24 25 26 28 I/O Bypass pin Connect pin 1 of the external gain setting resistor for right channel Connect pin 2 of the external gain setting resistor for right channel O Right channel negative output pin O Right channel positive output pin Description
Truth Table for Logic Inputs
Mute
0 0 0 0 0 0 0 0 1
Gain HP Mode Select Sense
0 0 0 0 1 1 1 1 X 0 0 1 1 0 0 1 1 X 0 1 0 1 0 1 0 1 X
Gain Mode of Power Amplifier
Unity Gain Setting Unity Gain Setting Unity Gain Setting Unity Gain Setting External Gain Setting External Gain Setting External Gain Setting External Gain Setting -
DC Vol. Control
Fixed Level Fixed Level Adjustable Adjustable Fixed Level Fixed Level Adjustable Adjustable -
BTL Output
Vol. Fixed Muted Vol. Adjustable Muted Vol. Fixed Muted Vol. Adjustable Muted Muted
SE Output
Vol. Fixed Vol. Adjustable Vol. Fixed Vol. Adjustable Muted
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APA4838
Typical Application Circuit
VDD
1 µF
VDD
R_var
DC Vol Control
VDD 100KΩ Internal gain select 3
20KΩ
20KΩ
HP Sense 100KΩ 21 5 Mute Mode 4 13
7
19
18
To Control Pin on Headphone Jack
Mode Control
20KΩ 10KΩ 10KΩ - Left Out 0.068µ F
Left Dock Left Audio Input 20KΩ 20KΩ 200KΩ Beep In Right Audio Input 200KΩ Right In Left In + 0.33µ F
11
Bias
10 20KΩ + 0.33µ F 20KΩ Right Dock VDD
Bias 28
9 20KΩ
1,8,14,20,23 GND 0.1µ F 0.1µ F 0.1µ F
2.2µ F
Bypass 22
10KΩ Click and Pop Suppression Circuitry 2 24
Shutdown 20KΩ 20KΩ
Copyright ANPEC Electronics Corp. Rev. A.1 - Apr., 2003
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-
Power Management
+
6,16,27
10KΩ 20KΩ 0.068µ F 25
+ -
Beep Detect
+
+ Volume Control 31 steps
12
+ 20KΩ 20KΩ
17
+ 220µ F 1KΩ Control Pin Pin Ring
15
+ Left Out To HP sense Circuit + Right Out Tip Sleeve
+
Headphone Jack 20KΩ 26 + 220µ F 1KΩ - Right Out
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APA4838
Application Information
Volume Control Table
Gain (dB) Low 0 -1 -2 -3 -4 -5 -6 -8 -10 -12 -14 -16 -18 -20 -22 -24 -26 -28 -30 -32 -34 -36 -38 -40 -42 -44 -46 -48 -50 -52 -78 77.5% 75.0% 72.5% 70.0% 67.5% 65.0% 62.5% 60.0% 57.5% 55.0% 52.5% 50.0% 47.5% 45.0% 42.5% 40.0% 37.5% 35.0% 32.5% 30.0% 27.5% 25.0% 22.5% 20.0% 17.5% 15.0% 12.5% 10.0% 7.5% 5.0% 0.0%
Voltage Range (% of Vdd) High 100.00% 78.5% 76.25% 73.75% 71.25% 68.75% 66.25% 63.75% 61.25% 58.75% 56.25% 53.75% 51.25% 48.75% 46.25% 43.75% 41.25% 38.75% 36.25% 33.75% 31.25% 28.75% 26.25% 23.75% 21.25% 18.75% 16.25% 13.75% 11.25% 8.75% 6.25% Recommended 100.000% 76.875% 74.375% 71.875% 69.375% 66.875% 64.375% 61.875% 59.375% 56.875% 54.375% 51.875% 49.375% 46.875% 44.375% 41.875% 39.375% 36.875% 34.375% 31.875% 29.375% 26.875% 24.675% 21.875% 19.375% 16.875% 14.375% 11.875% 9.375% 6.875% 0.000% Low 3.875 3.750 3.625 3.500 3.375 3.250 3.125 3.000 2.875 2.750 2.625 2.500 2.375 2.250 2.125 2.000 1.875 1.750 1.625 1.500 1.375 1.250 1.125 1.000 0.875 0.750 0.625 0.500 0.375 0.250 0.000
Voltage Range (Vdd=5V) High 5.000 3.938 3.813 3.688 3.563 3.438 3.313 3.188 3.063 2.938 2.813 2.688 2.563 2.438 2.313 2.188 2.063 1.938 1.813 1.688 1.563 1.438 1.313 1.188 1.063 0.937 0.812 0.687 0.562 0.437 0.312 Recommended 5.000 3.844 3.719 3.594 3.469 3.344 3.219 3.094 2.969 2.844 2.719 2.594 2.469 2.344 2.219 2.094 1.969 1.844 1.719 1.594 1.469 1.344 1.219 1.094 0.969 0.844 0.719 0.594 0.469 0.344 0.000
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APA4838
Typical Characteristics
THD+N vs. Frequency
10
VDD=5V RL=3Ω Po=1.8W BTL Av=2 Av=4 Av=8
THD+N vs. Output Power
10
VDD=5V RL=3Ω Av=2 BTL f=20KHz
THD+N (%)
THD+N (%)
1
1
0.1
0.1
f=20Hz
f=1KHz
0.01 20
100
1k
20k
0.01 10m
100m
1
3
Frequency (Hz)
Output Power (W)
THD+N vs. Frequency
10
VDD=5V RL=4Ω Po=1.5W BTL
THD+N vs. Output Power
10
VDD=5V RL=4Ω Av=2 BTL
THD+N (%)
1
Av=2 Av=4 Av=8
1
0.1
THD+N (%)
f=20KHz
0.1
f=1KHz
f=20Hz
0.01 20
100
1k
20k
0.01 100m
500m
1
3
Frequency (Hz)
Output Power (W)
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APA4838
Typical Characteristics (Cont.)
THD+N vs. Frequency
10
VDD=5V RL=8Ω Po=1.0W BTL
THD+N vs. Output Power
10
VDD=5V RL=8Ω Av=2 BTL
THD+N (%)
THD+N (%)
1
Av=2 Av=4 Av=8
1
f=20KHz
0.1
0.1
f=1KHz f=20Hz
0.01 20
100
1k
20k
0.01 10m
100m
1
2
Frequency (Hz)
Output Power (W)
THD+N vs. Frequency
10
VDD=5V RL=8Ω Po=250mW SE
THD+N vs. Output Power
10
VDD=5V RL=8Ω Av=1 SE
THD+N (%)
Av=1 Av=2 Av=4
THD+N (%)
1
1
f=20KHz
0.1
0.1
f=1KHz f=20Hz
0.01 20 100 1k 20k
0.01 10m
100m
500m
Frequency (Hz)
Output Power (W)
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APA4838
Typical Characteristics (Cont.)
THD+N vs. Frequency
10
VDD=5V RL=16Ω Po=150mW SE
THD+N vs. Output Power
10
VDD=5V RL=16Ω Av=1 SE
THD+N (%)
Av=1 Av=2
THD+N (%)
1
1
f=20KHz
0.1
Av=4
0.1
f=20Hz f=1KHz
0.01 20
100
1k
20k
0.01 10m
100m
300m
Frequency (Hz)
Output Power (W)
THD+N vs. Frequency
10
VDD=5V RL=32Ω Po=75mW SE
THD+N vs. Output Power
10
VDD=5V RL=32Ω Av=1 SE
THD+N (%)
1
1
THD+N (%)
f=20Hz f=20KHz
0.1
Av=1 Av=2 Av=4
0.1
f=1KHz
0.01 20 100 1k 20k
0.01 10m
50m
100m 200m
Frequency (Hz)
Output Power (W)
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APA4838
Typical Characteristics (Cont.)
THD+N vs. Frequency
10
VDD=5V RL=10KΩ Vo=1VRMS SE
THD+N vs. Output Swing
10
VDD=5V RL=10KΩ Av=1 SE
THD+N (%)
Av=1
THD+N (%)
1
1
0.1
Av=2 Av=4
0.1
f=20Hz f=20KHz f=1KHz
0.01 20
100
1k
20k
0.01 100m
500m
2
3
Frequency (Hz)
Output Swing (VRHS)
Crosstalk vs. Frequency
+0 -20 -40 -60 -80
R-ch to L-ch VDD=5V RL=8Ω Po=1.0W Av=2 BTL
Crosstalk vs. Frequency
VDD=5V RL=32Ω -20 Po=75mW Av=2 SE
+0
Crosstalk (dB)
Crosstalk (dB)
-40 -60 -80 -100
R-ch to L-ch L-ch to R-ch
-100
L-ch to R-ch
-120 20 100 1k 20k
-120 20 100 1k 20k
Frequency (Hz)
Frequency (Hz)
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APA4838
Typical Characteristics (Cont.)
Noise Floor vs. Frequency
100
Noise Floor vs. Frequency
100
No Filter
Noise Floor (µVRMS)
Noise Floor (µVRMS)
No Filter
A-Weight
10
10
A-Weight
VDD=5V RL=8Ω Av=2 BTL
1 20 100 1k 20k
VDD=5V RL=32Ω Av=1 SE
1 20 100 1k 20k
Frequency (Hz)
Frequency (Hz)
Supply Current vs. Supply Voltage
25 2 1 .8
Power Dissipation vs. Output Power
Power Dissipation (W)
Supply Current (mA)
20
1 .6 1 .4 1 .2 1 0 .8 0 .6 0 .4 0 .2 0 0 0 .5 1 1 .5
RL=8Ω
RL=3Ω
15
BTL
RL=4Ω
10
SE
5
No Load
VDD=5V Av=2 BTL
0 1 1 .5 2 2 .5 3 3 .5 4 4 .5 5 5 .5
2
2 .5
Supply Voltage (V)
Output Power (W)
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APA4838
Typical Characteristics (Cont.)
Power Dissipation vs. Output Power
0 .2 5
4 0 -4 -8
Gain vs. Voltage, 5V, SE
Power Dissipation (W)
0 .2
RL=8Ω
-1 2
Output Gain (dB)
VDD=5V Av=2 SE
-1 6 -2 0 -2 4 -2 8 -3 2 -3 6 -4 0 -4 4 -4 8 -5 2 -5 6 -6 0 -6 4 -6 8 -7 2 -7 6 -8 0
0 .1 5
RL=16Ω
0 .1
0 .0 5
RL=32Ω
0 0 0 .0 5 0 .1 0 .1 5 0 .2 0 .2 5 0 .3 0 .3 5 0 .4
VDD=5V AV=1 SE
0 0 .5 1 1 .5 2 2 .5 3 3 .5 4 4 .5 5
Output Power (W)
DC Vol Input Voltage (V)
Output Power vs. Supply Voltage
2 .2 5 2 160 140
Output Power vs. Supply Voltage
Output Power (W)
1 .5
THD+N=10%
Output Power (mW)
120 100
THD+N=10%
1
THD+N=1%
80 60 40 20 0
RL=32Ω Av=1 SE THD+N=1%
0 .5
RL=8Ω Av=2 BTL
0 2 .5 3 3 .5 4 4 .5 5 5 .5
2 .5
3
3 .5
4
4 .5
5
5 .5
Supply Voltage (V)
Supply Voltage (V)
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APA4838
Typical Characteristics (Cont.)
Output Power vs. Load Resistance
3 2.5
VDD=5V Av=2 BTL
Output Power vs. Load Resistance
800 700
VDD=5V Av=1 SE
2 1.5 1 0.5
THD+N=1%
Output Power (mW)
Output Power (W)
600 500 400 300 200 100 0
THD+N=10% THD+N=1%
THD+N=10%
0 48 16 24 32 40 48 56 64
48
16
24
32
40
48
56
64
Load Resistance (Ω)
Load Resistance (Ω)
PSRR vs. Frequency
+0 6
PSRR vs. Frequency
+0
VDD=5V Vin=100mVRMS RL=8Ω -20 Cbypass=2.2µF Av=1 SE
Ripple Rejection Ratio (dB)
-20
-40
Ripple Rejection Ratio (dB)
VDD=5V Vin=100mVRMS RL=8Ω Cbypass=2.2µF Av=2 BTL
-40
Gain Adjustable
Gain Adjustable
-60
-60
-80
Fixed Gain Mode
-80
Fixed Gain Mode
-100 20
100
1k
20k
-100 20
100
1k
20k
Frequency (Hz)
Frequency (Hz)
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APA4838
Typical Characteristics (Cont.)
Gain vs. Frequency
+12 +10 +8 +6 +4 +2 -0 20 100 1k 20k
VDD=5V RL=8Ω Av=2V/V BTL Cf=0.068µF Cf=0.22µF Cf=0.1µF
Gain (dB)
Frequency (Hz)
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APA4838
Application Descriptions
BTL Operation The APA4838 output stage (power amplifier) has two pairs of operational amplifiers internally, allowed for different amplifier configurations for each channel.
Gain 1 Gain 2
BTL Operation (Cont.) A BTL amplifier design has a few distinct advantages over the SE configuration, as it provides differential drive to the load, thus doubling the output swing for a specified supply voltage. Four times the output power is possible as compared
-Out
to a SE amplifier under the same conditions. A BTL configuration, such as the one used in APA4838, also
Volum e Control Am plifier output signal
OP1
creates a second advantage over SE amplifiers.
RL +Out
Since the differential outputs, +Right Out, -Right Out, +Left Out, and -Left Out, are biased at half-supply, no need DC voltage exists across the load. This eliminates the need for an output coupling capacitor which is required in a single supply, SE configuration. Single-Ended Operation Consider the single-supply SE configuration shown Application Circuit. A coupling capacitor is required to block the DC offset voltage from reaching the load. These capacitors can be quite large (approximately 33µF to 1000µF) so they tend to be expensive, occupy valuable PCB area, and have the additional drawback of limiting low-frequency performance of the system (refer to the Output Coupling Capacitor). The rules described still hold with the addition of the following relationship: 1 ≤ 1 1kΩ with rail-to-rail output and output coupling capacitor is required when using these outputs.
Tip
Headphone Jack
Figure 2: HP Sense input selection by phonejack plug
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APA4838
Application Descriptions (Cont.)
Docking Output Signal (Cont.) Typical values for the output coupling capacitors are 0.33µF to 1.0µF. If polarized coupling capacitors are used, connect their ’+’ terminals to the respective output pin. The Right Dock and Left Dock channel outputs signal are also used to driving internal volume control amplifier. Input Capacitor, Ci In the typical application an input capacitor, Ci, is required to allow the amplifier to bias the input signal to the proper DC level for optimum operation. In this case, Ci and the minimum input impedance Ri form a high-pass filter with the corner frequency determined in the follow equation: FC(highpass)= 1 2πRiCi (3) As other power amplifiers, proper supply bypassing is critical for low noise performance and high power supply rejection. The capacitors located on the bypass and power supply pins should be as close to the device as possible. The effect of a larger half supply bypass capacitor will improve PSRR due to increased halfsupply stability. Typical application employ a 5V regulator with 1.0µF and a 0.1µF bypass as supply filtering. This does not eliminate the need for bypassing the (4) supply nodes of the APA4838. The selection of bypass capacitors, especially Cbypass, is thus dependent upon desired PSRR requirements, click and pop performance. To avoid start-up pop noise occurred, the bypass voltage should rise slower than the input bias voltage and the relationship shown in equation (5) should be maintained. 1 1 200V 10ms , Itr > 100mA
Carrier Tape & Reel Dimensions
Po E P P1 D
t
F W
Bo
Ao
Ko D1
T2
J C A B
T1
A pp lication
A 330 ± 1
B 100 ref D 1.5 +0.1
C 13 ± 0.5 D1 1.5 min
J 2 ± 0.5 Po 4.0 ± 0.1
T1 16.4 ± 0.2 P1 2.0 ± 0.1
T2 2 ± 0.2 Ao
W 16 ± 0.3 Bo
P 12 ± 0.1 Ko
E 1.75 ± 0.1 t
TSSOP- 28
F 7.5 ± 0.1
6.9 ± 0.1 10.2 ± 0.1 1.8 ± 0.1 0.3 ± 0.05
(mm)
Copyright ANPEC Electronics Corp. Rev. A.1 - Apr., 2003 28 www.anpec.com.tw
APA4838
Cover Tape Dimensions
Application TSSOP- 28 Carrier Width 16 Cover Tape Width 21.3 Devices Per Reel 2000
Customer Service
Anpec Electronics Corp. Head Office : 5F, No. 2 Li-Hsin Road, SBIP, Hsin-Chu, Taiwan, R.O.C. Tel : 886-3-5642000 Fax : 886-3-5642050 Taipei Branch : 7F, No. 137, Lane 235, Pac Chiao Rd., Hsin Tien City, Taipei Hsien, Taiwan, R. O. C. Tel : 886-2-89191368 Fax : 886-2-89191369
Copyright ANPEC Electronics Corp. Rev. A.1 - Apr., 2003
29
www.anpec.com.tw
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