Megasan Elektronik-PMIC - Voltaj Regülatörü

PMIC - Voltaj Regülatörü - DC DC Lineer

- Üretici Part No
- Fiyat
- Satın Al
- Araçlar
- Stok
- Manufacturer
- Series
- Part Status
- Voltage - Input
- Voltage - Input (Max)
- Voltage - Dropout (Typical)
- Voltage Dropout (Max)
- Current - Supply (Max)
- Current - Quiescent (Iq)
- Current - Limit (Min)
- PSRR
- Number of Regulators
- Regulator Topology
- Voltage - Output
- Voltage - Output (Min/Fixed)
- Voltage - Output (Max)
- Current - Output
- Output Type
- Output Configuration
- Operating Temperature
- Mounting Type
- Package / Case
- Packaging
- Supplier Device Package
- Control Features
- Protection Features
- Üretici Part No
  
  TPS76350DBVRG4
  
  IC REG LINEAR TPS763 Positive Fixed 5V 150Ma SC-74A, SOT-753 T&R Texas
- Satın Al
- Araçlar
  - RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Texas Instruments
- Series
- Part Status
  
  Active
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  10V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  0.3V @ 150mA
- Current - Supply (Max)
  
  140µA
- Current - Quiescent (Iq)
  
  100µA
- Current - Limit (Min)
  
  -
- PSRR
  
  60dB (1kHz)
- Number of Regulators
  
  1
- Regulator Topology
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 125°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  SC-74A, SOT-753
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
  
  SOT-23-5
- Control Features
  
  Enable
- Protection Features
  
  Over Current, Over Temperature, Reverse Polarity
- Üretici Part No
  
  MIC5205-5.0YM5-TR
  
  IC REG LINEAR MIC5205 Positive Fixed 5V 150Ma SC-74A, SOT-753 T&R Microchip
- Satın Al
- Araçlar
  - RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Microchip Technology
- Series
- Part Status
  
  Active
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  16V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  0.35V @ 150mA
- Current - Supply (Max)
  
  2.5mA
- Current - Quiescent (Iq)
  
  150µA
- Current - Limit (Min)
  
  -
- PSRR
  
  75dB (100Hz)
- Number of Regulators
  
  1
- Regulator Topology
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 125°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  SC-74A, SOT-753
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
  
  SOT-23-5
- Control Features
  
  Enable
- Protection Features
  
  Over Current, Over Temperature, Reverse Polarity
- Üretici Part No
  
  L5150BNTR
  
  IC REG LINEAR L5150BN Positive Fixed 5V 150Ma TO-261-4, TO-261AA T&R STM
- Satın Al
- Araçlar
  - RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  STMicroelectronics
- Series
  
  Automotive, AEC-Q100
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  40V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  0.5V @ 150mA
- Current - Supply (Max)
  
  4.2mA
- Current - Quiescent (Iq)
  
  80µA
- Current - Limit (Min)
  
  -
- PSRR
  
  48dB (100Hz)
- Number of Regulators
  
  1
- Regulator Topology
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 150°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  TO-261-4, TO-261AA
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
  
  SOT-223
- Control Features
- Protection Features
  
  Over Temperature, Short Circuit
- Üretici Part No
  
  LP2985-50DBVR
  
  IC REG LINEAR LP2985 Positive Fixed 5V 150Ma SC-74A, SOT-753 (CT) Texas
- Satın Al
- Araçlar
  - RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Texas Instruments
- Series
- Part Status
  
  Active
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  16V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  0.58V @ 150mA
- Current - Supply (Max)
  
  2.5mA
- Current - Quiescent (Iq)
  
  95µA
- Current - Limit (Min)
  
  -
- PSRR
  
  45dB (1kHz)
- Number of Regulators
  
  1
- Regulator Topology
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 125°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  SC-74A, SOT-753
- Packaging
  
  Cut Tape (CT)
- Supplier Device Package
  
  SOT-23-5
- Control Features
  
  Enable
- Protection Features
  
  Over Current, Over Temperature, Short Circuit
- Üretici Part No
  
  TPS76350DBVR
  
  IC REG LINEAR TPS763 Positive Fixed 5V 150Ma SC-74A, SOT-753 (CT) Texas
- Satın Al
- Araçlar
  - RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Texas Instruments
- Series
- Part Status
  
  Active
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  10V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  0.3V @ 150mA
- Current - Supply (Max)
  
  140µA
- Current - Quiescent (Iq)
  
  100µA
- Current - Limit (Min)
  
  -
- PSRR
  
  60dB (1kHz)
- Number of Regulators
  
  1
- Regulator Topology
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 125°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  SC-74A, SOT-753
- Packaging
  
  Cut Tape (CT)
- Supplier Device Package
  
  SOT-23-5
- Control Features
  
  Enable
- Protection Features
  
  Over Current, Over Temperature, Reverse Polarity
- Üretici Part No
  
  AP2204K-5.0TRG1
  
  IC REG LINEAR AP2204 Positive Fixed 5V 150Ma SC-74A, SOT-753 T&R Diodes Inc.
- Satın Al
- Araçlar
  - RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Diodes Incorporated
- Series
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  24V
- Voltage - Dropout (Typical)
  
  0.5V @ 150mA
- Voltage Dropout (Max)
  
  0.5V @ 150mA
- Current - Supply (Max)
  
  2.5mA
- Current - Quiescent (Iq)
  
  50µA
- Current - Limit (Min)
  
  -
- PSRR
  
  60dB (100Hz ~ 1kHz)
- Number of Regulators
  
  2
- Regulator Topology
  
  -
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 85°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  SC-74A, SOT-753
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
  
  SOT-23-5
- Control Features
  
  Enable
- Protection Features
  
  Over Current, Over Temperature
- Üretici Part No
  
  TLE42794GXUMA1
  
  IC REG LINEAR 5V 150MA 8DSO Infineon
- Satın Al
- Araçlar
  - Not RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Infineon Technologies
- Series
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  45V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  0.5V @ 100mA
- Current - Supply (Max)
  
  8mA
- Current - Quiescent (Iq)
  
  -
- Current - Limit (Min)
  
  -
- PSRR
  
  70dB (100Hz)
- Number of Regulators
  
  1
- Regulator Topology
  
  -
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 150°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  8-SOIC (0.154", 3.90mm Width)
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
- Control Features
  
  -
- Protection Features
  
  Over Current, Over Temperature, Reverse Polarity, Short Circuit
- Üretici Part No
  
  TPS70950DBVR
  
  IC REG TPS709 LINEAR 5V 150MA SOT-23-5 T&R Texas
- Satın Al
- Araçlar
  - Not RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Texas Instruments
- Series
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  30V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  1.2V @ 150mA
- Current - Supply (Max)
  
  350µA
- Current - Quiescent (Iq)
  
  2.05µA
- Current - Limit (Min)
  
  -
- PSRR
  
  80dB ~ 52dB (10Hz ~ 1kHz)
- Number of Regulators
  
  1
- Regulator Topology
  
  -
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 125°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  SOT-23-5
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
- Control Features
  
  Enable
- Protection Features
  
  -
- Üretici Part No
  
  TPS7B6950QDCYRQ1
  
  IC REG TPS7B6950 LINEAR 5V 150MA SOT-223-4
- Satın Al
- Araçlar
  - Not RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Texas Instruments
- Series
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  40V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  0.8V @ 100mA
- Current - Supply (Max)
  
  -
- Current - Quiescent (Iq)
  
  25µA
- Current - Limit (Min)
  
  -
- PSRR
  
  60dB (100Hz)
- Number of Regulators
  
  1
- Regulator Topology
  
  -
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 150°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  TO-261-4, TO-261AA
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
- Control Features
  
  -
- Protection Features
  
  -
- Üretici Part No
  
  TPS70950QDRVRQ1
  
  IC REG TPS70950 LINEAR 5V 150MA 6WSON Texas
- Satın Al
- Araçlar
  - Not RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Texas Instruments
- Series
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  30V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  1.2V @ 150mA
- Current - Supply (Max)
  
  350µA
- Current - Quiescent (Iq)
  
  2.05µA
- Current - Limit (Min)
  
  -
- PSRR
  
  80dB ~ 52dB (10Hz ~ 1kHz)
- Number of Regulators
  
  1
- Regulator Topology
  
  -
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 125°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  6-WDFN Exposed Pad
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
- Control Features
- Protection Features
  
  -
- Üretici Part No
  
  TPS70950DRVT
  
  IC REG TPS70950 LINEAR 5V 150MA 6WSON Texas
- Satın Al
- Araçlar
  - Not RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Texas Instruments
- Series
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  30V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  1.2V @ 150mA
- Current - Supply (Max)
  
  350µA
- Current - Quiescent (Iq)
  
  2.05µA
- Current - Limit (Min)
  
  -
- PSRR
  
  80dB ~ 52dB (10Hz ~ 1kHz)
- Number of Regulators
  
  1
- Regulator Topology
  
  -
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 125°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  6-WDFN Exposed Pad
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
- Control Features
  
  Enable
- Protection Features
  
  -
- Üretici Part No
  
  TLV70450DBVT
  
  IC REG LINEAR 5V 150MA SOT23-5
- Satın Al
- Araçlar
  - Not RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Texas Instruments
- Series
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  24V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  1.1V @ 100mA
- Current - Supply (Max)
  
  5.5µA
- Current - Quiescent (Iq)
  
  4.5µA
- Current - Limit (Min)
  
  -
- PSRR
  
  60dB (100Hz)
- Number of Regulators
  
  1
- Regulator Topology
  
  -
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 125°C (TJ)
- Mounting Type
  
  Surface Mount
- Package / Case
  
  SOT-23-5
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
- Control Features
  
  -
- Protection Features
  
  Over Current, Reverse Polarity
- Üretici Part No
  
  TPS76350DBVTG4
  
  LDO Voltage Regulators Low-Power 150-Ma
- Satın Al
- Araçlar
  - Not RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Texas Instruments
- Series
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  10V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  0.3V @ 150mA
- Current - Supply (Max)
  
  140µA
- Current - Quiescent (Iq)
  
  100µA
- Current - Limit (Min)
  
  -
- PSRR
  
  60dB (1kHz)
- Number of Regulators
  
  1
- Regulator Topology
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 125°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  SOT-23-5
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
- Control Features
  
  Enable
- Protection Features
  
  Over Current, Over Temperature, Reverse Polarity
- Üretici Part No
  
  TPS709B50DBVR
  
  LDO Voltage Regulators 150-Ma, 30-V, Ultra-Low-Iq, Low-Dropout Voltage Regulator With Reverse Curre
- Satın Al
- Araçlar
  - Not RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Texas Instruments
- Series
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  30V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  1.2V @ 150mA
- Current - Supply (Max)
  
  350µA
- Current - Quiescent (Iq)
  
  2.05µA
- Current - Limit (Min)
  
  -
- PSRR
  
  80dB ~ 52dB (10Hz ~ 1kHz)
- Number of Regulators
  
  1
- Regulator Topology
  
  -
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 125°C
- Mounting Type
  
  Surface Mount
- Package / Case
  
  SOT-23-5
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
- Control Features
  
  Enable
- Protection Features
  
  Over Current, Over Temperature, Reverse Current, Under Voltage Lockout (UVLO)
- Üretici Part No
  
  TPS7B8450QDCYRQ1
  
  LDO Voltage Regulators Automotive 150-Ma, 40-V, Low-Dropout (LDO) Linear Regulator With Enable An
- Satın Al
- Araçlar
  - Not RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Texas Instruments
- Series
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  40V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  0.255V @ 150mA
- Current - Supply (Max)
  
  35µA
- Current - Quiescent (Iq)
  
  25µA
- Current - Limit (Min)
  
  -
- PSRR
  
  70dB (1kHz)
- Number of Regulators
  
  1
- Regulator Topology
  
  -
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 150°C (TJ)
- Mounting Type
  
  Surface Mount
- Package / Case
  
  TO-261-4, TO-261AA
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
- Control Features
  
  Enable
- Protection Features
  
  Over Current, Over Temperature, Under Voltage Lockout (UVLO)
- Üretici Part No
  
  AP2204-5.0-TRG1
  
  WIDE INPUT VOLTAGE AP2204-5.0-TRG1
- Satın Al
- Araçlar
  - Not RoHS
  - Belge İndir
- Stok
  
  0 Adet Stokta
- Manufacturer
  
  Diodes Incorporated
- Series
- Part Status
- Voltage - Input
  
  -
- Voltage - Input (Max)
  
  24V
- Voltage - Dropout (Typical)
  
  -
- Voltage Dropout (Max)
  
  0.5V @ 150mA
- Current - Supply (Max)
  
  2.5mA
- Current - Quiescent (Iq)
  
  50µA
- Current - Limit (Min)
  
  -
- PSRR
  
  60dB (100Hz ~ 1kHz)
- Number of Regulators
  
  1
- Regulator Topology
- Voltage - Output
  
  -
- Voltage - Output (Min/Fixed)
  
  5V
- Voltage - Output (Max)
  
  -
- Current - Output
  
  150mA
- Output Type
  
  Fixed
- Output Configuration
  
  Positive
- Operating Temperature
  
  -40°C ~ 85°C (TA)
- Mounting Type
  
  Surface Mount
- Package / Case
  
  TO-243AA
- Packaging
  
  Tape & Reel (TR)
- Supplier Device Package
- Control Features
  
  -
- Protection Features
  
  Over Current, Over Temperature

Hakkımızda

PMIC - Voltaj Regülatörü - DC DC Lineer

Filtre Listesi

Manufacturer

Series

Voltage - Input (Max)

Voltage - Dropout (Typical)

Voltage Dropout (Max)

Current - Supply (Max)

Current - Quiescent (Iq)

Current - Limit (Min)

PSRR

Number of Regulators

Regulator Topology

Voltage - Output

Output Type

Operating Temperature

Package / Case

Packaging

Stok Durumu:

RoHS:

Üretici Part No

TPS76350DBVRG4

Satın Al

Araçlar

Stok

Manufacturer

Series

Part Status

Voltage - Input

Voltage - Input (Max)

Voltage - Dropout (Typical)

Voltage Dropout (Max)

Current - Supply (Max)

Current - Quiescent (Iq)

Current - Limit (Min)

PSRR

Number of Regulators

Regulator Topology

Voltage - Output

Voltage - Output (Min/Fixed)

Voltage - Output (Max)

Current - Output

Output Type

Output Configuration

Operating Temperature

Mounting Type

Package / Case

Packaging

Supplier Device Package

Control Features

Protection Features

Üretici Part No

MIC5205-5.0YM5-TR

Satın Al

Araçlar

Stok

Manufacturer

Series

Part Status

Voltage - Input

Voltage - Input (Max)

Voltage - Dropout (Typical)

Voltage Dropout (Max)

Current - Supply (Max)

Current - Quiescent (Iq)

Current - Limit (Min)

PSRR

Number of Regulators

Regulator Topology

Voltage - Output

Voltage - Output (Min/Fixed)

Voltage - Output (Max)

Current - Output

Output Type

Output Configuration

Operating Temperature

Mounting Type

Package / Case

Packaging