Overview - Toshiba TCR15AG Series Reference Manual

1. Overview

For the purpose of requiring low power consumption application, it is general that average power
consumption goes down balancing total system utilization and supplying power. Especially
smartphone and tablet, there is a trade-off between the size and weight of the device and their
battery capacity while a high level of power management is necessary, but in the application there
are various electronic circuits including wireless communication, camera, display, audio, and storage
circuits, so it is necessary to control their power supplies surely.
Power management ICs (PMICs) are used in smartphones, tablets, and other small battery-
operated devices to achieve accurate power management. A PMIC consists of a few to a few dozen
power supply channels of DC-DC converters and low-dropout (LDO) regulators, and a controller to
control the on/off of each power supply and output according to commands from a main system-
on-a-chip (SoC). PMICs specifically designed for smartphone and tablet applications, are constrained
by size limits. Therefore, the power supply ICs integrated in some of these PMICs do not compare
favorably with discrete power supply ICs in terms of performance. The power supplies from a PMIC
might not satisfy system requirements, depending on the loads (ICs and modules) that they serve.
In addition, mobile devices with wireless communication capabilities might generate electromagnetic
interference (EMI) that affects bad impact to not only the communication quality but also internal
power supply circuits. PMICs are generally designed for applications that are not subject to frequent
remodeling. However, smartphones are upgraded frequently to add new features and improve
performance, and each upgrade entails changes to the specifications of internal circuits. It is
therefore impractical to rely on a single PMIC for the power management of all the internal circuits
from the viewpoints of both system design and PMIC design.
In addition, with the global uptake of the LTE wireless standard, many smartphone users now
share photographs and movies on SNS. This is driving substantial improvement in the performance
of smartphone cameras, which have a CMOS image sensor with low power consumption and high
read speed. Generally, it is necessary to supply different voltages to the sensor, core (control) and
I/O sections of a CMOS image sensor. The digital core of a CMOS image sensor that processes data
at high speed tends to consume a lot of power. Nowadays, the digital core is designed to operate at
a very low voltage (around 1 V) to reduce power consumption. In order to accommodate the
decreasing voltage and increasing current consumption, the power supply for the digital core needs
to have excellent AC characteristics, including a high power supply rejection ratio (PSRR) and a fast
load transient response, while providing a high current drive capability. Ultra-small packaging is also
an important factor for space-critical designs like smartphones.
In addition to the V
supply for the output circuit in order to achieve low dropout voltage and thus stable voltage
regulation even at low input voltage. The TCR15AG series provides outstanding PSRR and load
transient response required for CMOS image sensors for smartphone applications. In addition, the
TCR15AG series offers 46 LDO regulators with a fixed output voltage from 0.65V to 3.6V to meet a
wide range of application requirements. While providing accurate voltage regulation, all the LDO
regulators of the TCR15AG series are available in an ultra-small, thin-profile WCSP package.
© 2019
Toshiba Electronic Devices & Storage Corporation
input, Toshiba's LDO regulators of the TCR15AG series have a separate power
IN
3 / 18
RD030-RGUIDE-02
2019-05-08
Rev.2