Transcript What is SuPA?

Delivering MORE Together
What is SuPA?
SuPA: Supply for Power Amplifier
“SuPA” = DC/DC converter that provides an adaptive, optimized output power
supply for the RF PA to extend battery life and improve thermal performance
Traditional Approach:
Fixed Battery Supply to PA
VBATT
VBATT
VCC
RFIN
More Efficient Approach:
TI SuPA Adaptive Supply to PA
VCTRL
SuPA
VOUT
VOUT is optimized
for given POUT
VCC
RFOUT
RFIN
RFOUT
2
SuPA Benefit #1:
Reduced Battery Current Draw
• RF PAs have efficiencies between 4-40%  TI SuPA solution can
reduce battery current by 20%-50%
– Longer battery life
– Smaller battery form factor
– More voice/usage time
and coverage
3
SuPA Benefit #2:
Thermal Dissipation Improvement
• TI SuPA solution reduces worst case hot temperature by up to 30ºC
– Reduced thermal constraints
– Higher reliability
– Thinner, lighter phone design
90.5˚C
60.1˚C
Without SuPA
With SuPA
30˙C Temperature Reduction + 33% Power Savings
4
SuPA Key Characteristics
Differences vs Standard DC/DC Converter
• Higher Switching Frequencies
• Bypass Mode: ACB (Active Current Bypass)
• ACLR, EVM RF Compliance
5
Standard Buck vs. SuPA Buck
Digital core Buck
SuPA Buck
No Vcon pin needed for
changing output voltage
Typically operates at low
duty cycles
<25% to 60%
High efficiency over entire
output current range
Vcon pin critical for
changing output voltage
Operates over wide duty
cycles
10% to 100%
High efficiency over entire
output voltage range
Iq critical since it spends
more time in standby
Iq not that critical since PA
is a constant load ~30mA
to 50mA
Standard Buck vs. SuPA Buck (cont.)
Digital core Buck
Current Limit designed
to support max Iout
Transient response is
optimized for Line/Load
Transients
Start-up time not that
critical as long as it’s
below 700uS
Drop-out not critical and
no need for a Bypass
FET
SuPA Buck
Designed for Vcon
transients and max Iout
Optimized for Vcon
transients (output
voltage)
Critical, it must be less
than 50uS
Designed to provide
low output ripple and
smooth transition
Summary
SuPA: Supply for Power Amplifier
Benefits
– Reduced Battery Current Draw
– Thermal Dissipation Improvement
Different from a standard buck converter
ti.com/rfpower