HT9831 Datasheet, PDF (1/9 Pages) Holtek Semiconductor Inc – 315/433MHz ASK Transmitter

HT9831
315/433MHz ASK Transmitter
Features
· Complete UHF ASK transmitter
· Frequency range 300MHz to 450MHz
· Data rates higher than 10kbps
· Output Power up to 10dBm
Applications
· Car alarm Remote control
· Wireless PIR
· Remote Power Switches
· Low voltage operation - down to 2.0V
· Data tracking function for device wake-up
· Reference clock output
· 8-pin SOP/TSSOP packages
· Multi-Media Remote Control
· Remote Sensor Data Links
· Infrared Transmitter Replacement
General Description
The HT9831 is a highly integrated ASK transmitter IC for
remote wireless applications in the 300 to 450MHz fre-
quency band. This transmitter IC is a true ²data-in, an-
tenna-out² monolithic device making it very easy for
users to implement a wireless system. It is only neces-
sary to supply a crystal generated reference frequency,
which is the RF carrier frequency divided by 32, and a
few additional external parts to create a complete and
versatile transmitter. The HT9831 is capable of deliver-
ing +9.5dBm into a 50W load. This power level is possi-
ble due to a small form factor transmitter (lossy antenna)
which can operate near the maximum transmission reg-
ulation limit. The HT9831 utilises ASK/OOK - Amplitude
Shift Keying/On-Off Keying- UHF receiver types from
wide-band super-regenerative radios to narrow-band,
high performance super-heterodyne receivers. The
HT9831 minimum ASK data rate is 10kbps which sup-
ports a more complicated control protocol.
To minimise power consumption, the HT9831 provides
a data tracking function. In the Idle Mode, the internal
PLL will be switched off, but when high to low data is re-
ceived the PLL will be switched on and data will be
transmitted without delay. The PLL will be turned off au-
tomatically and the HT9831 will return to the Idle Mode
after no data input transients have been received for
more than 300ms. As there is a reference clock output
for the MCU, the MCU can use its internal RC clock
rather than using an additional crystal for precise timing.
With these combined features the HT9831 can provide
a power-saving and cost effective solution for a huge
range of remote wireless applications.
Block Diagram
EN
E n a b le
D IN
C o n tro l
XO UT
X IN
CREF
XTAL
D iv id e r
32X P LL
PA
P A _O U T
Rev. 1.20
1
November 5, 2014