ICs for Telephone AN6215S AGC IC for telephone speech network ■ Overview 1 8 2 7 3 6 4 5 5.0 ± 0.3 1.27 0.6 ± 0.3 0.4 ± 0.25 Unit: mm The AN6215S is an AGC IC for telephone speech network, and it incorporates an microphone input detection circuit and a receiver gain control circuit. It is especially best suited for cordless telephone thanks to a good speech tone quality obtained by reducing howling and echo sound. 4.2 ± 0.3 6.5 ± 0.3 1.5 ± 0.2 0.3 5 6 7 8 VCC SOP008-P-0225A Det. VREF Buff 4 3 2 1 CC GND ■ Block Diagram 0.1 ± 0.1 • Operation with wide power supply voltage range from 2.1 V to 6.0 V • Enlargement of dynamic range by incorporating a variable VREF circuit that varies according to the supply voltage • Possible to adjust the received voice attenuation amount with an external resistor • Possible to adjust the AGC operating point with an external resistor • Possible to design with fewer external components 0.15 0.65 ■ Features 1 AN6215S ICs for Telephone ■ Pin Descriptions Pin No. Symbol Description 1 GND 2 ∆GAIN Variable gain adjustment pin 3 RX IN Receiver signal input pin 4 RX OUT Receiver signal output pin 5 TX DET Transmitter signal detection pin 6 TX IN 7 VC VREF control pin 8 VCC Supply voltage pin Ground pin Transmitter signal input pin ■ Absolute Maximum Ratings Parameter Symbol Rating Unit Supply voltage VCC 6.5 V Supply current ICC 3.0 mA PD 19.5 mW Topr −20 to +75 °C Tstg −55 to +125 °C Power dissipation Operating ambient temperature Storage temperature * * Note) *: Except for the operating ambient temperature and storage temperature, all ratings are for Ta = 25°C. ■ Recommended Operating Range Parameter Supply voltage Symbol Range Unit VCC 2.1 to 6.0 V ■ Electrical Characteristics at Ta = 25°C Parameter Symbol Conditions Min Typ Max Unit Operating current *1 ICC Operating time at no signal input 1.4 2.0 mA Receiver amp. voltage gain *1 GRX RX in = −20 dBm 1.5 3.5 5.5 dB Receiver amp. output D range *1 VORX Output voltage at THD = 5% 0 2 dBm Receiver amp. variable gain width *1, *2 ∆Gain Receiver amp. gain variation between TX in = −50 dBm and TX in = −30 dBm −10 −8 −6 dB High-level VREF control sink current ICH VCH = 3 V 25 50 µA High-level VREF control voltage VCH Pin 7 voltage range in a base-set mode 1.5 VCC V Low-level VREF control voltage VCL Pin 7 voltage range in a hand-set mode 0 0.5 V Note) 1. VCC = 5.0 V, f = 1 kHz unless otherwise specified. 2. *1: Pin 7 DC voltage sets to VCH = 5.0 V *2: ERO-25CKF6802 produced by Matsushita Electronic Components Co. is used for RX in = −30 dBm. (Refer to " ■Application circuit example".) 2 ICs for Telephone AN6215S ■ Electrical Characteristics at Ta = 25°C (continued) • Design reference data Note) 1. The characteristics listed below are theoretical values based on the IC design and are not guaranteed. 2. VCC = 5.0 V, f = 1 kHz unless otherwise specified. Parameter Symbol Detection circuit input impedance ZIDET Detection circuit gain Conditions Min Typ Max Unit Pin 5 input impedance 50 Ω GDET R in = 10 kΩ 27 dB Receiver amp. input impedance ZIRX Pin 3 input impedance 25 kΩ Receiver amp. output wave distortion factor THD VORX = −10 dBm (80 kHz LPF) 0.3 % Receiver amp. output noise voltage NORX Wide band −65 dBm Receiver amp. output impedance ZORX Pin 4 output impedance 1 kΩ Sidetone control operation voltage VDET DC voltage of pin 5 when sidetone control operates 0.3 V Sidetone control ∆Gain variation rate ∆R ∆RX out/∆TX in at TX in = −39 dBm − 0.6 dB/dB Base set mode VREF voltage VRB Pin 4 DC voltage at pin 7 = high 2 V Hand set mode VREF voltage VRH Pin 4 DC voltage at pin 7 = low 1.15 V ■ Terminal Equivalent Circuits Pin No. Equivalent circuit 1 Description ∆GAIN: Gain adjustment pin Gain width of receiver amp. can be changed by changing the external resistance. R1 to large → Gain width becomes Receiver amp. large. R1 to small → Gain width becomes small. 2 2 1.15 V 3 R1 I2 17 µA 68 kΩ 25 kΩ 3 C1 0V DC 1.15 V RX IN: Receiver signal input pin Input receiver sound signal from line. Input impedance is 25 kΩ. VREF 4 Typical wave GND: Ground pin Receiver amp. 4 C2 Receiver signal To receiver amp. RX OUT: Receiver signal output pin Connect receiver amp. etc. Output impedance is approximately 50 Ω. 3 AN6215S ICs for Telephone ■ Terminal Equivalent Circuits (continued) Pin No. Equivalent circuit Description 5 Typical wave TX DET: Transmitter signal detection pin DC Full wave detection 5 To receiver amp. R3 100 kΩ 100 kΩ C3 10 µF 6 Connect a smoothing capacitor and a resister to adjust attack-recovery time of transmitter signal detection. Detection amp. gain is determined by the following equation: 100 (kΩ) × 3 G= R4 (kΩ) C3 large → Attack time becomes long. R3 small → Recovery time becomes short. With capacitor DC Input Without capacitor TX IN: Transmitter signal input pin Input transmitter sound signal C4 6 Detection R4 Transmitter signal 5 7 VH/VL 7 100 kΩ 10 kΩ 180 kΩ 8 4 VC: Reference voltage control pin Reference voltage VREF becomes 2 V when voltage is high, and becomes 1.15 V when voltage is low. Normally, reference voltage is set to VREF = 2 V when it is used for a baseset, and to VREF = 1.15 V when it is used for a hand-set. DC VCC: Supply voltage pin Connect supply voltage. DC ICs for Telephone AN6215S ■ Application Circuit Example • System configuration • Detects input of microphone and gives attenuation to a receiver system • Operating point and variable width of attenuator can be set with external resistor respectively. R Microphone amp. Speech amp. T Circuit I/F Microphone C4 R1 VCSW R3 C3 5 6 7 8 VCC Det. VCSW: VREF control switch SW on: VREF = 2.0 V SW off: VREF = 1.15 V VREF Buff GND R1: Detection circuit gain adjustment resistor R2: Receiver ∆Gain width adjustment resistor R3, C3: Resistor and capacitor to determine attack-recovery time of transmitter 4 3 2 1 CC R2 C1 C2 Receiver amp. Receiver amp. BN • Characteristics RX out RX out Inclination: ∆R = − 0.6 dB/dB ∆Gain = − 8 dB (R2 = 68 kΩ) TX in Figure 1. Variable width of attenuation VREF (V) 2.0 VRB (Base-set mode) 1.15 VRH (Hand-set mode) 0.3 −39 dBm (R1 = 10 kΩ) TX in Figure 2. Operating point of attenuation VDET Reference voltage VCC Figure 3. Operation of variable VREF circuit 5