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LG Electronics U250 service manual GSM PAM U101 SKY77318, GSM PAM Schematic

Models: U250

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3. TECHNICAL BRIEF

3.5.5 GSM PAM (U101 : SKY77318)

The SKY77318 is an extremely small (6 x 6 mm), GSM PAM for handset applications. This module has been optimized for excellent efficiency and Pout while maintaining high GSM/GPRS efficiency. The small size and high performance is achieved with high-reliability GaAs HBT technology.

With 50Ω and output, no external matching or bias components are required. The module incorporates two highly-integrated GaAs power amplifier die with a BiCMOS controller.

Each amplifier has three gain stages with on-die inter-stage matching implemented with a high Q passives technology for optimal performance. The CMOS controller implements a fully integrated power control within the module for GSM operations, and serves as the GPRS operations. This eliminates the need for any external couplers, power detectors, current sensing etc., to assure the output power level. The module has Tx enable and band select inputs. Module construction is a low- profile overmolded land-grid array on laminate.

L115

18nH

 

Rev.D

 

 

 

 

C123

C121

C124

L403

0.01u

33u

100p

1.5nH L116

GSMRAPA

 

 

10nH

 

 

 

100ohm

R107

 

C441

C438

C134

 

0.01u

 

5.6p

100p

 

 

 

+VPWR

EGSM NA5.6nH

L406 2.7nH

8.86dB Rev.1.0

C137

NA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C139

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C138

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NA

 

 

 

68p

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

20

 

 

17

 

 

6

 

 

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

 

 

 

 

VAPC

 

 

VBATT

 

 

VCC1B

 

VCC1A

 

 

3

 

 

 

 

 

 

 

 

 

DCS_PCS_OUT

 

 

 

 

 

 

DCS_PCS_IN

 

 

 

11

 

 

 

 

 

 

4

 

 

EGSM_OUT

 

 

U101

 

 

EGSM_IN

 

 

 

 

19

 

 

 

 

18

 

 

RSVD_GND

 

 

 

 

 

 

 

 

 

 

 

ENABLE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

21

P_GND

SKY77318

 

 

BS

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GND9 GND8

GND7

GND6

GND5

GND4 GND3

GND2

GND1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

16

14

13

12

10

9

8

7

5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C136

0.01u

 

 

FL101

 

 

 

91 R110

 

 

 

 

 

 

 

 

 

 

 

4

5

 

 

 

 

 

 

O1

G3

1

 

 

 

 

 

 

IN

 

 

 

 

 

 

G2

G1

 

 

 

R113

100ohm

GSM_PA_EN

3

2

 

R114

100ohm

 

 

 

 

 

C149

 

 

 

 

 

 

15p

 

EFCH897MTDB1

 

 

R117 100ohm

GSM_PA_BAND

 

 

 

 

 

C153

GSM_PA_BAND

MODE

 

 

 

 

15p

 

 

 

 

LOW

GSM

 

 

 

 

 

 

 

 

 

 

 

 

HIGH

DCS/PCS

 

 

 

 

 

 

 

 

R108

51

7.5dB

R112

39

R115

DCS_PCS_TX

R11191

GSM_TX 100ohm

[Figure 1. 8] GSM PAM Schematic

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LG Electronics U250 service manual GSM PAM U101 SKY77318, GSM PAM Schematic
Page 28 Page 30

U250 specifications

The LG Electronics U250 is a distinguished device known for its cutting-edge features and innovative technologies within the mobile phone sector. Launched as part of LG's effort to cater to a growing demand for functional yet stylish smartphones, the U250 boasts an array of characteristics that appeal to a savvy clientele.

One of the primary features of the U250 is its impressive display. Sporting a vibrant screen that offers excellent color reproduction and clarity, it enhances the user experience for gaming and multimedia consumption. The responsive touchscreen interface allows for seamless navigation, making it user-friendly for all age groups.

The U250 is powered by a robust processor that ensures smooth performance, whether multitasking between applications or running demanding games. With ample RAM, it minimizes lag and enhances the overall operating experience, allowing users to switch effortlessly between tasks.

Photography enthusiasts will appreciate the U250's advanced camera system. It is equipped with a high-resolution primary camera that captures stunning images in various lighting conditions. The inclusion of features like autofocus and image stabilization significantly elevates the quality of photos and videos. Additionally, the front-facing camera is designed for high-quality selfies and video calls, ensuring that users can always stay connected.

The device supports a range of connectivity options, including 4G LTE, Bluetooth, and Wi-Fi, ensuring users can remain connected to the world around them. The integration of NFC technology also enables quick and convenient transactions, particularly useful in a cashless society.

Battery life is another standout characteristic of the U250. With a durable battery, it offers extended usage time, allowing users to go through their day without the constant worry of recharging. Coupled with fast-charging capabilities, it reduces downtime significantly.

The LG U250 runs on an intuitive operating system that provides easy access to a plethora of apps on the platform. Customization options are abundant, allowing users to tailor their device's appearance and functionality to suit their preferences.

In conclusion, the LG Electronics U250 combines striking design with versatile functionality, making it a formidable entry in the smartphone market. With its impressive display, powerful performance, advanced camera features, and strong battery life, the U250 is poised to meet the needs of modern users seeking both style and substance in a mobile device. Whether for work or leisure, this smartphone is designed to enhance everyday life.