ISD1400 SERIES
5. PIN DESCRIPTION
PIN NAME
PIN NO
FUNCTION
A0-A7
1-6, 9, 10
Address Inputs: The address inputs have two functions,
depending on the level of the two Most Significant Bits (MSB)
of the address.
If either or both of the two MSBs are LOW, the inputs are all
interpreted as address bits and are used as the start address
for the current record or playback cycle. The address pins are
inputs only and do not output internal address information as
the operation progresses. Address inputs are latched by the
falling edge of PLAYE , PLAYL , or REC .
If both A6 & A7 are HIGH, then the device is in special
operational modes. Please refer to operational modes section
for details.
NC
7, 8, 11, 22
12, 13
NC: No Connect
VSSD, VSSA
Ground: Similar to VCCA and VCCD, the analog and digital
circuits internal to the ISD1400 series use separate ground
buses to minimize noise. These pins should be tied together
as close as possible to the device.
SP+, SP-
14, 15
Speaker Outputs: The SP+ and SP- pins provide direct drive
for loudspeakers with impedances as low as 16 Ω. A single
output may be used, but, for direct-drive loudspeakers, the
two opposite-polarity outputs provide an improvement in
output power of up to four times over a single-ended
connection. Forthermore, when SP+ and SP- are used, a
speakercoupling capacitor is not required. A single-ended
connection will require an AC-coupling capacitor between the
SP pin and the speaker. The speaker outputs are in a high-
impedance state during a record cycle, and held at VSSA
during power down.
VCCA, VCCD
16, 28
17
Supply Voltage: Analog and digital circuits internal to the
ISD1400 series use separate power buses to minimize noise
on the chip. These voltage buses are brought out to separate
pins on the package and should be tied together as close to
the supply as possible. It is important that the power supply
be decoupled as close to the package as possible.
MIC
Microphone: The microphone input transfers its signal to the
on-chip preamplifier. An on-chip Automatic Gain Control
(AGC) circuit controls the gain of this preamplifier from –15 to
24dB. An external microphone should be AC coupled to this
pin via a series capacitor. The capacitor value, together with
the internal 10 KΩ resistance on this pin, determines the low-
frequency cutoff for the ISD1400 series passband. See
Winbond’s Application Information for additional information
on low-frequency cutoff calculation.
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WINBOND [ WINBOND ]
