Philips Semiconductors
0.95 V starting power unit
Preliminary specification
TEA1202TS
1 FEATURES
• Fully integrated battery power unit, including complete
DC-to-DC converter circuit, two Low Drop-Out voltage
regulators (LDOs) and a battery low detector
• Configurable for 1, 2 or 3-cell Nickel-Cadmium (NiCd)
or Nickel Metal Hybrid (NiMH) batteries and 1 Lithium
Ion (Li-Ion) battery
• Guaranteed DC-to-DC converter start-up from 1-cell
NiCd or NiMH battery, even with a load current
• Upconversion or downconversion
• Internal power MOSFETs featuring a low RDSon of
approximately 0.1 Ω
• Synchronous rectification for high efficiency
• Soft start
• PWM-only operating option
• LDO drop-out voltage of 30 mV at 50 mA
• Both LDOs can also be used as low-ohmic power
switches
• Stable LDO performance with ceramic capacitors
• At start-up, LDO1 can be loaded
• Stand-alone low battery detector requires no additional
supply voltage
• Low battery detection level at 0.90 V, externally
adjustable to a higher level
• Adjustable output voltages
• Shut-down function
• Small outline package
• Advanced 0.6 µm BICMOS process.
2 APPLICATIONS
• Cellular phones
• Cordless phones
• Personal Digital Assistants (PDAs)
• Portable audio players
• Pagers
• Mobile equipment.
3 GENERAL DESCRIPTION
The TEA1202TS is a fully integrated battery power unit
including a high efficiency DC-to-DC converter which runs
from a single-cell NiCd or NiMH battery, two low drop-out
voltage regulators and a low battery detector. The circuit
can be arranged in many ways to optimize the application
circuit of a power supply system. Therefore, most inputs
and outputs are separated, the DC-to-DC converter can be
arranged for upconversion or downconversion and the
regulators can also be used as power switches. One
regulator can be used completely independent of the rest
of the system, and the low battery detector can be
configured for several types of batteries. Accurate low
battery detection is possible while all other blocks are
switched off.
The DC-to-DC converter features efficient, compact and
dynamic power conversion using a digital control concept
comparable with Pulse Width Modulation (PWM) and
Pulse Frequency Modulation (PFM), integrated CMOS
power switches with a very low RDSon and fully
synchronous rectification.
The device operates at a switching frequency of 600 kHz
which enables the use of external components with
minimum size. The switching frequency can be
synchronized to an external high frequency clock signal.
Optionally, the device can be kept in PWM control mode
only. Deadlock is prevented by an on-chip undervoltage
lockout circuit.
Active current limiting enables efficient conversion in
pulsed-load systems such as Global System for Mobile
communication (GSM) and Digital Enhanced Cordless
Telecommunications (DECT).
Both LDOs show a low drop-out voltage and are inherently
stable, even when ceramic capacitors with a low ESR
value are applied at the outputs. Usage of the LDOs as
low-ohmic switches is also possible.
LDO1 can be loaded at start-up.
The low battery detector has a built-in detection level
which is optimum for a single-cell NiCd or NiMH battery.
Higher battery voltages can be translated to this single-cell
level by an additional built-in LDO circuit.
4 ORDERING INFORMATION
TYPE
NUMBER
TEA1202TS
NAME
SSOP20
PACKAGE
DESCRIPTION
plastic shrink small outline package; 20 leads; body width 4.4 mm
VERSION
SOT266-1
2002 Mar 14
3