$str = 'текст ДПБ02 текст еще';
echo $str . PHP_EOL;
if (preg_match_all('/([А-Я]*)(\d*)/iu', $str, $matches, PREG_SET_ORDER)) {
foreach ($matches as $index => $match) {
if (count(array_filter($match))) {
echo '#' . $index . ' ' . $match['1'] . ' ' . $match['2'] . PHP_EOL;
}
}
}