User Manual
Table Of Contents
- 1. Introduction
- 2. GR47/GR48 Radio Devices
- 3. Abbreviations
- 4. Mechanical Description
- 5. System Connector Interface
- 5.1 Overview
- 5.2 General Electrical and Logical Characteristics
- 5.3 Grounds
- 5.4 VCC - Regulated Power Supply Input
- 5.5 Battery Charging Input (CHG_IN)
- 5.6 Turning the Radio Device ON/OFF and the External Power Signal
- 5.7 Analogue Audio
- 5.8 PCM Digital Audio
- 5.9 Serial Data Interfaces
- 5.10 SIM Card Related Signals
- 5.11 Service/Programming
- 5.12 Buzzer
- 5.13 LED
- 5.14 General Purpose Digital I/O Ports
- 5.15 Extended I/O capabilities
- 5.16 General Purpose Analogue I/O Ports
- 5.17 External I 2C Serial Control Bus
- 5.18 TX_ON - Burst Transmission
- 5.19 Real Time Clock
- 6. Antenna Connector
- 7. Keyboard Interface
- 8. Hints for Integrating the Radio Device
- 9. Embedded Applications
- 10. TCP/IP Stack
- 11. Technical Data
- 12. Declaration of Conformity
- 13. Introduction to the Developer’s Kit
- 14. Using the Developer’s Kit
5. SYSTEM CONNECTOR INTERFACE
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LZT 123 7589 R1A
Hard Shutdown Sequence
Figure 5.4 Hard Shutdown Sequence
(4) To implement the Hard Shutdown of the GR47, the ON/OFF pulse must
be held low until the sequence is complete. Ensure that ON/OFF is not
released before VIO has been deactivated by the module.
5.6.1 VIO - 2.75V Supply
VIO provides an output voltage derived from an internal 2.75V regulator.
Its electrical characteristics are shown below.
You can use this output for the following:
• to indicate that the radio device is powered;
• to power interface circuits, external to the radio device.
ON/OFF
VIO
t
HSD
t
PULSE
Symbol Parameters Conditions Min. Typ Max Unit
t
+6'
Time to complete
hardware
shutdown
2-11s
t
38/6(
Application ON/
OFF pulse width
ON/OFF low
until VIO is
disabled
t
+6'
10 - s
Parameter Min. Typ. Max. Units
Output Voltage (I
load
= 50 mA) 2.70 2.75 2.85 V
Load current 75 mA