NCP2809BDMR2G ON Semiconductor, NCP2809BDMR2G Datasheet - Page 14

• Manufacturer Part Number: NCP2809BDMR2G
• Description: IC AMP STEREO AUD 135ME MICRO-10
• Manufacturer: ON Semiconductor
• Series: NOCAP™r
• Type: Class ABr

Specifications of NCP2809BDMR2G

• Output Type: Headphones, 2-Channel (Stereo)
• Max Output Power X Channels @ Load: 135mW x 2 @ 16 Ohm
• Voltage - Supply: 2.2 V ~ 5.5 V
• Features: Depop, Short-Circuit and Thermal Protection, Shutdown
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: NCP2809BDMR2G; NCP2809BDMR2GOSTR

Detailed Description
2.6 V to 5.0 V power supply. It delivers 24 mW
power to a 16 W load (V
power to a 16 W load (V
identical internal power amplifiers; NCP2809A has a fixed
internal gain of 0 dB and the gain can be set externally with
the NCP2809B.
Internal Power Amplifier
designed to deliver the specified output power without
clipping. The channel resistance (R
transistors does not exceed 3.0 W when driving current.
composed of three symmetrical gain stages, first and
medium gain stages are transconductance gain stages in
order to maximize bandwidth and DC gain.
Turn−On and Turn−Off Transitions
corresponding to curves in Figures 38 to 41.
transitions, output power in the load must be slowly
established or cut. When logic high is applied to the
shutdown pin, the bypass voltage begins to rise
exponentially and once the output DC level is around the
common mode voltage, the gain is established slowly
(50 ms). This way to turn−on the device is optimized in
terms of rejection of “pop and click” noises.
the following formula.
enters in shutdown mode:
turned to zero internally as shown in Figure 41.
exponential discharge of the bypass voltage. It is then tied
to Ground as shown in Figure 40.
Shutdown Function
is low. During the shutdown mode, the DC quiescent
current of the circuit does not exceed 600 nA.
The NCP2809 power audio amplifier can operate from
The structure of NCP2809 is basically composed of two
The output P
The structure of the internal power amplifier is
A Turn−on/off transition is shown in the following plot
In order to eliminate “pop and click” noises during
A theoretical value of turn−on time at 25°C is given by
C
R: Internal 300 k resistor with a 25% accuracy
When logic is turned low on shutdown pin, the device
− 50 ms later the audio signal is cut off as the gain is
− 385 ms later, the DC signal will reach 0.7 V due to
A theoretical approach of this time is:
The device enters shutdown mode when shutdown signal
by
: Bypass Capacitor
T
T
on
off
= 0.95 * R * C
= R * C
mos
by
and N
* Ln(V
P
P
mos
by
= 2.4 V) and 131 mW
= 5.0 V).
p
transistors of the amplifier are
/1.4)
on
) of the N
APPLICATION INFORMATION
mos
rms
rms
and P
http://onsemi.com
output
output
mos
14
Current Limit Protection Circuitry
135 mW, V
the load of 130 mA.
when a short−circuit occurs, the current limit in the load is
fixed to 250 mA. The current in the output MOS transistors
is real−time monitored, and when exceeding 250 mA, the
gate voltage of the corresponding MOS transistor is clipped
and no more current can be delivered.
Thermal Overload Protection Circuitry
exceeds 160°C, and will be switched back on only when the
temperature goes below 140°C.
NCP2809 is a stereo power audio amplifier.
output coupling capacitors, then the current provided by
the battery for one output is as following:
•
•
So, the total power delivered by the battery to the device is:
The power in the load is P
V
I
O
The maximum output power of the circuit (P
In order to limit excessive power dissipation in the load
Internal amplifiers are switched off when temperature
If the application requires a Single Ended topology with
p
V
consider a sine wave signal with a period T and a peak
voltage V
R
(t)
/R
L
O
L
(t) is the AC voltage seen by the load. Here we
is the load.
P TOT + V p
P TOT +
I p avg + 1
P
O
= 5.0 V, R
.
T/2
2p
V p .V o
p.R L
P OUT +
L
I p avg
= 16 W) requires a peak current in
p
0
OUT
V o
R L
.
T
V O 2
2R L
sin(t)dt +
p.R L
V o
Orms
TIME
=