AS3688 datasheet(10/72 Pages) AMSOSRAM

10 / 72 page

AS3688

austriami crosyst ems

Datasheet, Confidential

www.austriamicrosystems.com (ptr,tje)

Revision 1.1.1 / 20060707

8 - 70

Figure

8 – RGB Current Sinks RGB1 vs. V(RGB1)

Detailed Functional Description

7.1

Analog LDO

The Analog LDOs (VANA1, VANA2) is designed to supply power to sensitive analog circuits like camera supply,

LNAs, Transceivers, VCOs, and other critical RF components of cellular radios. Additionally, the Analog LDO is

suitable for supplying power to audio devices or as a reference for A/D and D/A converters.

The design is optimized to deliver the best compromise between quiescent current and regulator performance for

battery powered devices.

Stability is guaranteed with ceramic output capacitors (see Figure 3) of 1µF ±20% (X5R) or 2.2µF +100/-50%

(Z5U). The low ESR of these capacitors ensures low output impedance at high frequencies. Regulation

performance is excellent even under low dropout conditions, when the power transistor has to operate in linear

mode. Power supply rejection is high enough to suppress ripple on the battery caused by the PA in TDMA

systems. The low noise performance allows direct connection of noise sensitive circuits without additional filtering

networks. The low impedance of the power transistor enables the device to deliver up to 150mA even at nearly

discharged batteries without any decrease in performance.

The LDO is off by default after startup (apply voltage on VDD_GPIO)

0,0

0,5

1,0

1,5

2,0

V(RGB1) [V]

RGB1=38.25mA

RGB1=4.8mA

0,0

0,5

1,0

1,5

2,0

V(CURR1) [V]

CURR1=76.8mA, curr3x_strobe_high=0

CURR1=10.2mA, curr3x_strobe_high=0

CURR1=76.8mA, curr3x_strobe_high=1

AS3688 Datasheet(PDF) 10 Page - ams-OSRAM AG