Switching Driver. NJU8789 Datasheet
Monaural BTL Output Clock-less Switching Driver for Class D Amplifier
The NJU8789 is a monaural BTL output switching driver
for class D amplifier including Separated Power Source
terminals between Input and Output. It converts 1bit
digital signal input, such as PWM or PDM signal.
The NJU8789 realizes very high power-efficiency by
class D operation. Therefore, It is suitable for portable
set with speaker.
Clock-less switching driver
1-channel 1bit Audio Signal Input
Monaural BTL Output
Standby(Hi-Z) Control Function
Operating Voltage : 1.8V to 4.5V
: VDD to 4.5V
1 VDD − Power Supply
− Output Power Supply
VSS − GND terminal
2 IN I 1-bit Data Input Terminal
O Positive output
O Negative output
Standby Control Terminal
Maker test Terminal
L: Normal operation
3 NC − Non connection
*VSS(Terminal No.6,10) should be connected at a nearest point to the IC.
INPUT TERMINAL STRUCTURE
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(1) IN terminal (Input Signal)
The input signals are PWM signals or PDM signals.
(2) OUTP and OUTN terminal (Output Signal)
The OUTP and OUTN generate PMW output signal The NJU8789 drives a speaker by the BTL output, and
OUTP is a positive output and OUTN is a negative outputs.
A switching regulator with a high response against a voltage fluctuation is the best selection for the VDDO,
which is the power supply for output drivers.
(3) Standby Control Function
By setting the STBYb terminal to “L”, the NJU8789 becomes standby condition. During standby condition,
OUTP and OUTN are in Hi-Z.
The STBYb terminal must be connected to VDD when not using the Standby Function.