PTB48500 Datasheet, PDF (1/14 Pages) Texas Instruments – Dual-Output, 48-V Input Isolated DC/DC Converter for xDSL

PTB48500, PTB48501, PTB48502
Dual-Output, 48-V Input Isolated
DC/DC Converter for xDSL
SLTS218B - SEPTEMBER 2003 - REVISED NOVEMBER 2004
Features
• Dual Outputs
(Independently Regulated)
• Input Voltage Range:
36 V to 75 V
• Power-up/Down Sequencing
• 1500 VDC Isolation
• Over-Current Protection
• Over-Temperature Shutdown
• Under-Voltage Lockout
• Fixed Frequency Operation
• Temp Range: –40 to 100 °C
• Industry Standard Outline
• Operates with PTB4851x for
Complete AC7 Power Solution
• Powers up to 64 DSL Ports
• Safety Approvals:
UL/cUL 60950
EN 60950
Description
The PTB4850x power modules are a
dual-output isolated DC/DC converter,
designed to provide the logic supply volt-
ages for AC-7 based xDSL applications.
The PTB48500 is rated for 13 A of total
output current, making it suitable for
32-channel xDSL applications. The
PTB48501 and PTB48502 provide output
current for powering up to 64 xDSL chan-
nels. The PTB48501 is rated for 16.5 A
total output current, and the PTB48502,
21 A. The PTB48502 incorporates 10 W
of additional capacity for powering periph-
eral circuitry. Any of these converters can
be used for other applications with simi-
lar power requirements.
The modules operate from a standard
telecom (-48 V) central office (CO) supply
and include an “on/off” enable control,
Stand-Alone Application
output current limit, over-temperature
protection, input under-voltage lockout
(UVLO). The PTB48500 and PTB48501
also incorporates a power-up reset (POR)
output.
The modules are designed to operate
with one of the PTB4851x DC/DC con-
verter modules. The combination of a
PTB4850x and PTB4851x converter
provides the complete the power supply
for an AC7 chipset. The “EN Out” and
“Sync Out” pins provide compatible out-
put signals for controlling both the power
up sequence and switching frequency of
the PTB48510.
The PTB4850x modules employ
double-sided surface mount construction,
and are an industry standard size.
Pin Configuration
Pin Function
1 +VI
2 Sync Out
3 Enable #
4 EN Out
5 –VI
6 +VO 2
7 COM
8 POR* / COM †
9 Vo2 Adjust
10 +VO 1
Shaded functions indicate signals
that are referenced to –V_I.
# Denotes positive logic:
Open = Normal operation
–VI
= Outputs Off
* Denotes negative logic:
High = Normal operation
Low = Reset
† This pin is COM on the PTB48502
+VI
Sync Out ²
1 _+VI
EN Out ⁴
PTB4850x
* Pin 8 is ‘COM’ on PTB48502
POR ^{(8) *}
Vo₁
–V_I
Vo1 ¹⁰
5 _–VI
Vo2 ⁶
Vo2
3 _Enable
Vo2 Adj ⁹
L
L
O
O
A
A
D
D
COM ^{7, (8) * COM}
For technical support and further information visit http://power.ti.com