Denon DRA-100, Service Manual

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IP5900 (IC1004)
Block Diagram
Pin Discription
PIN
NAME TYPE DESCRIPTION
DSBGA WSON
A1 4 EN I
Enable input; disables the regulator when ≤ 0.4 V. Enables the regulator when ≥ 1.2 V. An
internal 1-M Ω pull-down resistor connects this input to ground.
A2 6 IN I Input voltage supply. A 0.47-μF capacitor should be connected at this input.
B1 3 GND -
Common ground
B2 1 OUT O
Output voltage. A 0.47-μF Low ESR capacitor should be connected to this Pin. Connect this
output to the load circuit.
- 2 NC - No internal connection.
-
Thermal
Pad
Thermal
Pad
-
The exposed thermal pad on the bottom of the package should be connected to a copper
area on the PCB under the package. The use of thermal vias to remove heat from the package
into the PCB is recommended. Connect the thermal pad to ground potential or leave floating.
Do not connect the thermal pad to any potential other than the same ground potential seen
at device pin 3. For additional information on using TI's Non Pull Back WSON package, see
Application Note AN-1187 (SNOA401).
1 OUT
2 N/C
3 GND
IN 6
N/C 5
Bottom View
Thermal
Pad
OUT 1
N/C 2
GND 3
6 IN
5 N/C
Top View
4 EN EN 4
Thermal
Pad
IN
A2
OUT
B2
IN
A2
OUT
B2
A1
EN
B1
GND
A1
EN
B1
GND
Top View Bottom View
LP5900
www.ti.com SNVS358Q –JULY 2005–REVISED FEBRUARY 2015
5 Pin Configuration and Functions
DSBGA (YZR and YPF) Packages
4 Pins
WSON Package with Exposed Thermal Pad (NGF)
6 Pins
Pin Functions
PIN
NAME TYPE DESCRIPTION
DSBGA WSON
EN I Enable input; disables the regulator when ≤ 0.4 V. Enables the regulator when ≥
A1 4
1.2 V. An internal 1-M Ω pull-down resistor connects this input to ground.
A2 6 IN I Input voltage supply. A 0.47-µF capacitor should be connected at this input.
B1 3 GND — Common ground
OUT O Output voltage. A 0.47- μ F Low ESR capacitor should be connected to this Pin.
B2 1
Connect this output to the load circuit.
— 2 NC — No internal connection.
The exposed thermal pad on the bottom of the package should be connected to a
copper area on the PCB under the package. The use of thermal vias to remove
heat from the package into the PCB is recommended. Connect the thermal pad to
Thermal
— Thermal Pad — ground potential or leave floating. Do not connect the thermal pad to any potential
Pad
other than the same ground potential seen at device pin 3. For additional
information on using TI's Non Pull Back WSON package, see Application Note
AN-1187 ( SNOA401 ).
Copyright © 2005–2015, Texas Instruments Incorporated
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Product Folder Links: LP5900
IN
V
BG
1.2 V
+
EN
GND
POR
+
OUT
V
IH
R
F
C
F
+
EN
EN
1 M  
LP5900
SNVS358Q –JULY 2005–REVISED FEBRUARY 2015 www.ti.com
7 Detailed Description
7.1 Overview
Designed to meet the needs of sensitive RF and analog circuits, the LP5900 provides low noise, high PSRR, low
quiescent current, as well as low line and load transient response figures. Using new innovative design
techniques, the LP5900 offers class-leading noise performance without the need for a separate noise filter
capacitor.
7.2 Functional Block Diagram
7.3 Feature Description
7.3.1 No-Load Stability
The LP5900 will remain stable and in regulation with no external load.
7.3.2 Enable Control
The LP5900 Enable (EN) pin is internally held low by a 1-M Ω resistor to GND. The EN must be higher than the
V
IH
threshold to ensure that the device is fully enabled under all operating conditions. The EN pin voltage must
be lower than the V
IL
threshold to ensure that the device is fully disabled.
7.3.3 Low Noise Output
Any internal noise at the LP5900 reference voltage is reduced by a first order low-pass RC filter before it is
passed to the output buffer stage. This eliminates the need for the external bypass capacitor for noise
suppression.
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